Over the years, I have come across instances where issues have arisen, such as the filters blinding prematurely.  With testing, this has ultimately been identified as leaving the tank open in a paper mill, and an investigation of the elements highlighted this, along with the high particle counts. 

There have been other root causes, such as mineral oil being added to a phosphate ester oil on an electro-hydraulic control system, or, in another case, the oil supplier putting engine oil in drums intended for turbine oil.  In the latter case, within less than an hour of topping up the turbine tank with just one of the mislabelled drums, the filters were showing as blocked, and the turbine was out of service for six months.

Within less than an hour of topping up the turbine tank with just one mislabelled drum, the filters were blocked, and the turbine was out of service for six months.

A more confusing scenario was a switch in supplier for a bearing oil at a paper mill.  The end-user was assured of compatibility, but it transpired that a difference in the additive package, combined with water ingress (it was a paper mill after all), led to deposits on the filter.  This could so easily have been checked by a filter-compatibility test from the new oil supplier.  Filter companies often offer this service as well.

Consequently, I tend to use the following checklist when clients experience sudden, premature filter blockages in a previously stable system.

In the first instance, however, it is always useful to ask what the last maintenance action was, as this is often the cause or at least a clue to the possible cause. 

While a number of these were major incidents involving high costs, I still frequently encounter the “oil is just oil” issue, and top-ups on smaller machines have been made with the wrong oil.

I still frequently encounter the “oil is just oil” issue, and top-ups on smaller machines have been made with the wrong oil.

Typically, I might get a phone call along the lines of “Is it possible to see if the wrong oil has been used for a top-up?”  To which my answer is always, “Let me guess, you found the wrong container next to the asset?”  Invariably, the answer is always yes. 

Field Checks Before the Lab

So, when it comes to testing for the wrong oils used as top-ups, before even considering a laboratory test, there are a few basics to consider first.

What the Lab Results Reveal

When it comes to laboratory testing, ideally, two samples need to be sent: a sample of the correct oil from a container in the store, along with the suspect sample from the asset.  Using a sample of the correct oil, fresh from a container, a reasonable baseline for inorganic additive levels can be established and used for comparison with the suspect oil.

In terms of testing, however, apart from the obvious chemical and physical properties, measured wear rates may be affected by incorrect oil, which will elevate the measured wear metals. 

Ultimately, though, several lessons spring to mind that we would do well to remember:

1. Training and raising awareness of the need to avoid cross-mixing oils
2. The use of a color code system for lubricants, with the color code visible on the new containers in stores, on handling equipment, and on assets.
3. Guarantees backed up by insurance coverage from the suppliers when switching lubricant brands, but ideally, with technical testing.
4. Certificates of conformity for all new batches of lubricants supplied.
5. Random sampling of new oils, particularly for the high-cost assets.

What’s the Right Number of Lubricants for Your Plant?

Over the years, I have been to sites with either too many or too few lubricant types.

Both scenarios are potentially costly.

On the one hand, too many types of lubricant are costly in terms of purchase price and ultimately risk downtime due to the wrong lubricant being used.

On the other hand, too few lubricant types are costing the company due to overzealous consolidation, leading to a possible substandard lubricant specification in use.

Why Do Lubricant Inventories Get Out of Hand?

Generally, I find that where too many lubricant types exist, usually differing brands, is the result of procurement blindly following the Original Equipment Manufacturer (OEM) insistence on a brand for “Warranty reasons”.  Legally, the OEM should provide a recommended lubricant specification and include a list of brands.  However, if a non-recommended brand can be shown to meet or exceed the required specification, the warranty issue is no longer a concern, especially if the OEM is contacted and obtains written approval. 

I have been through this process on several occasions, especially on new builds, where various electric motor and pump suppliers will try to enforce a particular brand, sometimes for commercial rather than technical reasons.

Where too many lubricant types exist, usually differing brands, is the result of procurement blindly following the OEM insistence on a brand for warranty reasons.

Another possibility is that the procurement team is shopping around for the best pricing, resulting in numerous brands in the storeroom.  This has happened in both small, family-run businesses and in larger operations where a procurement contractor is responsible and is shopping for the best deal. 

What Makes Lubricant Consolidation Worth the Effort?

Primarily, the main reason is cost-benefit.

Purchasing fewer lubricant types means each remaining type in use is purchased in greater volumes, thereby realizing potential cost savings through negotiated discounts for higher volumes. 

This goes further: particularly with oils, these can be bought in larger container sizes, further reducing the purchase price, as typically the larger the container, the cheaper the unit cost.  However, while handling small pails is cheap, handling drums is more complex. Still, with the installation of a “best practice” bulk storage system, the oil can be purchased in drums but handled and transferred via smaller, more easily managed, sealable, and refillable containers that also meet “best practice” guidelines.

A secondary cost reason is the reduced risk of using the wrong lubricant and the resulting damage from cross-contamination.

This latter issue, however, is also the result of a lack of “best practice” with no tagging of the machines and no internal company policy of colour-coding the lubricants, either, allied to poorly written work orders that lack detail.

Is There a Business Case for Consolidation?

Yes…and no.

Be careful of being penny-wise and pound-foolish, as we say in the UK, or should that be cents-wise and dollars-foolish?

Let’s clarify.  In the late 1990s, working with BP, they stated that the average customer will spend less than 1% of their annual maintenance budget buying lubricants, but will spend more than 40% of it dealing with the outcomes of poor lubrication practices on site.

To put that into context, with a $10 million annual maintenance budget, less than $100,000 is spent on lubricants, while $4 million is spent on repairs, rebuilds, and other downtime costs associated with poor lubrication management.

So, would you rather chase a $20,000 savings or deal with an internal issue costing $4 million and recover at least $1 million of that?

The average customer will spend less than 1% of their annual maintenance budget buying lubricants, but will spend more than 40% of it dealing with the outcomes of poor lubrication practices.

In my opinion, the cost-benefit of a lubricant consolidation exercise will also depend on the industry type.  In some instances, certain industries, such as Food & Beverage and Pharma, have limited lubricant ranges, with consolidation already underway, particularly for NSF-approved Food-Grade lubricants, and limited asset types. 

On the other hand, Oil & Gas, mining, Pulp & Paper, for example, not only have a larger range of lubricants to suit a wide variety of asset types, but these industries will also utilise greater quantities, especially in fluid power systems, engines, transmissions, and turbine trains for compressors or power generation.

The Right Way to Consolidate Your Lubricant Program

Lubricant consolidation, in my opinion, is again an essential first step in implementing a world-class lubrication management programme.  Apart from getting a handle on all the lubricants on site, it will help identify obsolete stock, address issues arising from product name changes, and create a plan for the discontinued and hard-to-obtain products still on the list.

Ideally, using internal or sub-contracted, independent expertise, a list of the lubricants in use should be compiled at the beginning.  This is a useful exercise, as I often find multiple duplicates in Enterprise Resource Planning systems (SAP, Maximo, etc.) for lubricant accounting codes.  While each container size of a lubricant type should have its own accounting code, there are often instances where procurement has inadvertently added another, but under a slightly different term, for example, as 15-40 instead of the original 15W-40.

Once the duplicates have been removed, the list should be tabulated in a spreadsheet with columns denoting the brand, product, and then further itemized by column headings not only for the base oil type, thickener type, and intended application, but also relevant to the lubricant type, showing the physical, chemical, and performance properties.

 I would then prioritise the lubricants, with the highest priority given to those used in critical assets or specialised equipment that must remain, and the lowest to those in general applications and low-criticality assets.

However, be aware that, for greases. At the same time, it is tempting to use a multi-purpose grease for the motors; the base oil’s viscosity may be too high compared to a specialist electric motor bearing grease, which can increase power consumption.

In addition, gearboxes and transmissions need investigation, as Sulphur-Phosphorus-based Extreme Pressure oils may not suit all designs. In fact, apart from the chemical issue with the S_P EP oils, which require a solid-suspension type physical EP oil, some gears may only need an Anti-Wear oil.

Rather than dumbing down to the cheapest level, take the opportunity to raise the bar to the highest level.

A final comment here is that rather than dumbing down to the cheapest level, take the opportunity to raise the bar to the highest level.  For example, switching from mineral to synthetic base oils may seem counterintuitive in terms of cost; however, there are several benefits.  The higher VI of the synthetic base oils may help consolidate into different Viscosity Grade oils, while potential cost benefits include longer oil change intervals and reduced energy consumption.

What Comes After Consolidation?

While the consolidation may be your only objective, the cost-benefit of such a process will be limited and, in fact, incur additional costs due to downtime resulting from uncertainty about the new lubricant range and cross-contamination. 

In addition, it is simply not possible to start topping up with a revised oil grade, such as an ISO VG 22 synthetic oil, on a gearbox currently using an ISO VG 320 mineral oil. Hence, the likelihood is that the consolidation won’t happen.

Further, even if consolidation reduces the number of lubricant types in use, it may still result in a variety of container sizes or require purchasing smaller containers at a higher unit cost unless steps are taken to address processing with larger containers in the lubricant store.

Simply put, the real benefit comes from a structured process of improvement across the whole lubrication management strategy.

Should You Let Your Supplier Run the Consolidation?

It is, of course, possible, and increasingly, lubricant vendors are going down this road with their clients.  A strong supplier with your best interests as the end user at heart is the ideal approach.  Unfortunately, I have seen too many instances of a cursory review of the lubricants resulting in over-consolidation to the detriment of the machinery.

One outcome of creating a spreadsheet, as mentioned earlier, is the generation of an internal lubricant specification document.  With actual product names removed, the folder of specifications for each lubricant can be shared with all suppliers as part of a single-source procurement process.  This means that, without the current product name, the lubricant supplier must review the specification document in detail, note its properties and performance criteria, and recommend a suitable lubricant.

What Are the Benefits of a Single Lubricant Supplier?

Just as there is a cost-benefit to lubricant consolidation, rationalising the supplier base can also realise cost savings.  Buying all the lubricants from one source will also help push for discounts beloved of bulk purchasing.

There are other benefits to single sourcing, too.  When evaluating responses to the tendering process, a single-source supplier is more likely to support the process once in place.  Naturally, this depends on the volume of business, but a single-source supplier is more likely to commit to your process of improving the lubrication management strategy.

With actual product names removed, the folder of specifications for each lubricant can be shared with all suppliers as part of a single-source procurement process.

Of course, a single-source supplier may not be able to cover all lubricants, so some allowance will need to be made for specialist lubricants.

What’s the Big Picture Here?

While a cost-benefit, the desire for lubricant consolidation should not be driven by procurement looking to maximise short-term savings, especially by avoiding the temptation to err on the side of cheaper, lower-performing products. 

Lubricant consolidation should be driven by reliability professionals looking to improve the overall lubrication strategy, in which knowledge of future improvements in storage and handling will enable more effective consolidation decisions, maximising the cost-benefit.

When the lube room resembles a crime scene – chaotic storage, unlabeled containers, questionable handling tools, inconsistent transfer practices – it becomes a hidden driver of accelerated wear, additive depletion, ingress-driven contamination, and component life variability that will never show up cleanly in maintenance reports.

The condition of the lube room often mirrors the true reliability culture more accurately than any KPI dashboard. These conversation starters expose the systemic, upstream issues that quietly undermine asset reliability long before oil ever reaches a machine.

25 Lube Room Conversation Starters

1. Why do unlabeled or ambiguously labeled containers still circulate – and who verifies contents before use?
2. What process ensures transfer equipment is flushed, capped, and stored correctly to maintain cleanliness targets per the ISO 4406 cleanliness standard?
3. Why does incoming oil fail our cleanliness specifications – and are we actually verifying ISO 4406 codes instead of relying on supplier paperwork?
4. Who is accountable for lubrication storage standards – and why is “nobody” still the default?
5. Are lubricants grouped by base oil, viscosity grade, and additive chemistry – or simply by whichever shelf is empty?
6. Why are new desiccant breathers sitting idle while storage containers exchange unfiltered air?
7. Why are open funnels or unsealed top-off containers still acceptable when they are proven contamination pathways?
8. If drums are stored horizontally, are the bungs positioned at 3 and 9 o’clock to maintain seal integrity?
9. Do we routinely verify incoming lubricant quality (particle count, viscosity per ASTM D445, AN/BN) against the OEM Certificate of Analysis – or assume delivered product meets specification?
10. Why is moisture control reactive when water accelerates oxidation, depletes additives, and destabilizes boundary films?
11. Have we consolidated lubricant options to the lowest reasonable minimum?
12. Why is the filter cart treated as an emergency tool instead of being used as part of a repeating task to filter all critical sumps routinely?
13. How often do we audit lubricant shelf life – especially for products nearing manufacturer-recommended limits (typically 2–5 years depending on chemistry and storage conditions)?
14. What ISO 4406 cleanliness code targets do we require for stored lubricants – and do we confirm incoming product meets those targets before use?
15. Are grease cartridges stored to prevent temperature cycling and oil separation – or do we assume the sealed packaging eliminates all risks?
16. What controls prevent “clean” top-off containers from becoming contamination sources after weeks of exposure?
17. Why is faded Sharpie still our primary labeling method instead of standardized, controlled identification?
18. Do we maintain a documented lube room SOP – or rely on tribal knowledge that evaporates with personnel turnover?
19. Why do spills persist long enough to become permanent floor features despite OSHA 1910.22 housekeeping requirements and slip-risk implications?
20. Why do we allow partially used containers to sit uncapped, accelerating airborne particulate ingress?
21. How many lubrication-related failures begin right here in the lube room long before a technician touches a machine?
22. Are the open-stores containers protected from temperature extremes, high atmospheric pollution, and high humidity to help maintain additive stability and prevent condensation?
23. What is our process for removing expired or degraded lubricants – before they become “mystery blends” applied during outages?
24. Is the lube room organized as a contamination-control system – or just as a more efficient way to store lubricants?
25. If a new hire walked in today, would the lube room reinforce excellent lubrication practices – or accelerate the spread of bad habits?

A modern lube room isn’t a storage closet – it’s a contamination-control and quality-assurance environment. When lubricants are stored under controlled conditions, verified for cleanliness, transferred with discipline, and protected from environmental stressors, machine reliability increases before any wrench is turned.

Cleaning up the lube room is not cosmetic work; it’s one of the highest-leverage steps a plant can take to stabilize lubrication quality, extend asset life, and reduce avoidable failures. These conversation starters expose the upstream weaknesses that sabotage reliability – and point the way toward transforming the lube room into a controlled, engineering-grade operation.

Over the years, the one thing that has always struck me is how few reliability teams work with their counterparts in the Health and Safety and Environmental departments.

Linking Lubrication to ESG and Sustainability Goals

To quote the guru, Ron Moore, in his article, “A Reliable Plant – Good for Personal and Process Safety”:

Compelling data from operating plants has been provided to demonstrate that “a reliable plant is a safe plant, is a cost-effective plant, is an environmentally friendly plant.” The reverse was also shown, that is, an unreliable plant is less safe, more costly, and less environmentally friendly.

This is something that I trot out in every training session, whether it be an awareness class or a certification preparation class.  Yet I sense there is still a “them and us” attitude between reliability engineers and their colleagues on the other side, and vice versa.

I want to focus on the environmental benefits in this article as they are fundamental to sustainability.  A quick trawl of LinkedIn and, of course, a rapid scan of most corporate mission statements, one is bound to see Sustainability mentioned.  Just how serious are we about this, or is it simply paying lip service to a perceived wish from the public at large?

I believe that the majority of the general public is concerned about the environment and the impact that it may have, and hence the proliferation of electric cars.  I believe companies are also concerned, perhaps more so as a result of the penalty to comply and the cost in terms of environmental damage and the punitive costs that result.

So, if companies are serious about sustainability, how can lubrication assist in the challenge for a more sustainable operation?

Why Reliability and Lubrication Are Sustainability Cornerstones

Let’s start with the issue of reliability.  Lubrication is, call it what you will, a cornerstone, a foundation block, or a core element of reliability.  Without a successful lubrication strategy based on best practice, reliability is doomed to mediocrity at best.

• When equipment runs smoothly, without unnecessary stops and breakdowns, then the emissions are lessened, and this also avoids the energy spikes that a start-up generates.
• With longer-lasting components and machines resulting from improved reliability, fewer emissions are created by re-manufacturing and shipping of the replacement parts and units.
• With longer lubricant life, there is less risk of spillages and leakages, and reduced deliveries to the site.
• With all the above, the strain on natural resources is diminished.

That, in a nutshell, is lubrication-focused sustainability.

Essentially, any business seeking to be more sustainable needs to put an effective lubrication strategy in place as part of its reliability drive.

However, that isn’t all of it. What else can be done to achieve greater levels of sustainability that also aid in the reduction of costs?

Reduction of costs? Surely sustainability costs?  For once, we have a win-win scenario!

Let’s start by looking at some of the simpler aspects.

Simple Lubrication Changes That Deliver Big Sustainability Gains

The first option is to switch from spin-on oil filters to simply replacing the elements.  A spin-on filter requires an element, as well as a core support tube and a housing, the latter two typically being of metal.  On disposal, this is a larger, heavier unit needing specialised disposal owing to the oil contamination.

However, going back to the traditional idea of a removable housing, with the core support tube as part of the filter head, then we have only the element to dispose.  This is something that the automotive industry has returned to, with all new cars now typically just needing the element replaced.  Here’s the win-win: less damage to the environment and cheaper element replacements.

Labyrinth or non-contact seals versus the elastomer lip seal are another opportunity, particularly with process pumps with significantly higher shaft speeds.  In addition to providing better sealing and reducing contamination ingress, the elastomer lip’s rubbing contacts cause less damage to the shaft, resulting in reduced friction and wasted power. 

However, work by Heinz Bloch showed that while the superior seals are more expensive, the life-cycle cost was still significantly less than that of the simple elastomer lip seal—another win-win scenario for the environment and the profits.

Reducing Waste and Costs Through Smarter Lubricant Handling

Buying lubricants in larger volume containers is a further opportunity for win-win. 

Going back to the mid-1990s, I recall many companies transitioning from buying lubricants in the 208L drums to buying in smaller 20L and 25L pails.  Similarly, grease transitioned from the 20kg and 25kg kegs to the 400g plastic tubes.  Understandably, this was partly a move to safer handling by having smaller packaging without the need for the handling equipment that heavy (more than 180kg) oil drums required, whilst 400g tubes of grease meant there was no longer the need to hand pack grease guns.

So why transition back to the older, less safe ways?  Again, sustainability, yet with a win-win situation.

In researching pricing, it is often the case that for a container of fifty times the quantity of grease, the cost is only ten times more than that of the 400g tube.  With oil, the proportionate volume differential from 20L to 208L to 1000L (ten times and 50 times, respectively) is eight times and thirty-six times, respectively.  In my experience, buyers are always looking for the lowest price on lubricants! 

Apart from the costs, think of the disposal issues associated with fifty plastic tubes compared to one metal pail. A further issue I find with the 20L and 25L pails, and even the smaller 400g tubes of grease, is the amount of waste.  Volumes of 1L or more of new oil are often disposed of as the pail is near empty, and some remaining new grease is often discarded in the 400g tubes, which, over time and a reasonable throughput of these small containers, adds up to a considerable cost and impact on the environment.

Balancing Bulk Purchasing With Safe Handling Practices

But what about the handling issues?  For many sites, such volumes are deemed unnecessary due to the numerous small-volume sumps. The volume of grease used is considered so low that it is not worth the larger volumes, especially given the health and safety risks associated with manual packing of grease guns, as well as the added contamination.

There’s an easy solution to these problems that addresses the issue of both safety and the environment, albeit at a small price of an investment.  Frankly, though, these would be part of any best practice strategy in any case, but it is useful to justify the installation by linking the safety and sustainability aspects to the reliability needs.

For the oils, the automated tank units allow for oil to be purchased in the 208L drums with dispensing into the smaller sealable and refillable containers.  This will require the use of appropriate handling equipment for the movement of the drums.

Images from Enluse/OilSafe

For the grease, the cleanest way to fill the grease, with caution, is to use a drum pump.  Most large containers of grease get left open and become contaminated, whereas using this method eliminates that problem.  Fit a grease nipple to the gun in place of the vent, and then backfill the gun via a pump fitted to the larger 20/25kg pail.

Do not over-pressurize while filling!

Just from some of the examples above, it can be seen that aspects of lubrication can contribute significantly to reducing waste as well as cost.  However, let’s keep in mind that irrespective of these, a reliable plant is a sustainable plant.  Any company pushing its sustainability agenda should start with reliability.

Challenges in Grease Selection Without Full Bearing Specifications

Bearing manufacturers have provided a significant amount of detailed advice for lubricant selection, application, and replenishment.  Formulas used by the machine designers incorporate details that are typically not readily available to the maintenance practitioner, namely load rating and ratio, grease L₁₀ lifecycle, and specific bearing dimensions. 

 The bearing diameters (OD, ID) may be satisfactorily estimated, but there are multiple bearing models for a bearing type that will share a bore dimension.  Without the correct bore and outer diameter, it is impossible to arrive at an exact replacement volume.

The Role of Grease Viability in Replacement Frequency

 Grease viability drives replacement frequency. Grease Viability is best determined by testing.  Per DIN 51825, greases can be evaluated under laboratory conditions to deliver a provisional expected lifecycle, with results reported in either L₁₀ or L₅₀ values. The grease’s L₁₀ and L₅₀ values depict operating hours to 90% and 50% viability. The frictional measurement of a loaded bearing in the FE8 test stand determines grease viability. 

Without grease viability data, replacement frequency is always an educated guess.

 When the grease can no longer separate and protect surfaces during test conditions, it is evidenced by an increase in friction beyond a threshold. At this point, the test hours are noted, and the grease is assigned a value in hours for grease viability. These values are not often published for customer use. Without these discrete pieces of information for the greased bearing, estimating the best replacement frequency is challenging.

Engineering Principles for Reliability-Centric Grease Relubrication

Suppose the machine owner wants to use machine lubrication as a leading practice to improve machine reliability. In that case, the machine owner must invest time to fully define the bearing and lubricant details to calculate appropriate volumes and intervals to deliver reliability-centric lubrication practices.

 This article presents the engineering principles for bearing grease relubrication, including consideration for open, single, and double shielded bearing configurations, and will include both theoretical methods and general advice useful to calculate both volumes and intervals when the exact details are not available.   The calculations presented here are also used to define volume and frequency for operating conditions.

Even without full specs, sound engineering principles can guide precise grease relubrication.

 Bearing manufacturers have provided detailed advice for selecting lubricant type, volume, and frequency requirements. They intend to assist the user with placing the optimum volume of a lubricant product with viscometric properties and surface performance (AW and EP) additives that precisely address the operating parameters (heat, load, vibration, moisture, contaminant, process chemical challenges).

Once accomplished, the user can expect the grease to feed oil to the race incrementally between the current date and the planned replenishment date so that the replacement practice provides a seamless flow of lubricant to the load zone, as depicted in Figure 1.

Either too much or too little grease, and/or inappropriately high or low oil viscosity causes viscous drag and/or destruction of the bearing surfaces and lubricant within the bearing. 

In moderate and high-speed bearings (nDm > 150K), even slight variations in consistency of replenishment and fill volume produce effects including dry surfaces and elevated high-frequency vibration (inadequate feed), elevated temperatures and increased energy consumption (overfeed).

The faster the shaft speed, and the higher the load, the more pronounced the deficiencies. As the shaft speed decreases, the negative impact (churning, overheating, and energy losses) declines, but is still evident. The first part of this multi-part document addresses lubricant viscosity and NLGI selection. 

The second part addresses volume and frequency. The third part addresses sealed and shielded bearings and electric motor configurations.

Lubricant Selection: Viscosity, Additives, and NLGI Grade

Understanding the Impact of Viscosity on Bearing Performance

Viscosity changes with temperature and pressure. As temperature increases, viscosity decreases, and as pressure increases, viscosity increases. These factors are interdependent on one another. The central questions for selecting the correct lubricant grade for a given brand and product are:

1. What is the minimum acceptable viscosity for a given bearing?
2. What is the optimum viscosity for the bearing at operating temperature?
3. What is the viscosity of the current lubricant at the normalized bearing (machine) operating temperature?

Determining the minimum allowable viscosity to sustain element and race separation (EHD film formation) is a simple calculation, as follows:

V_min= 27,878 * RPM ^-0.7114  * Dm ^-0.52

Where:

V_min   = minimum allowable viscosity

RPM = shaft rotational speed

Dm    = bearing mean diameter

For example, assuming the bearings on a 254-frame-size motor are operating at 2400 RPM, and contain single row deep groove ball bearings with a bore diameter (ID) of 45 mm and an outer diameter (OD) of 85 mm, then the pitch diameter is 65 mm. The minimum allowable oil thickness for EHD film formation would be 12.505 centistokes at operating temperature.  The optimum operating viscosity will be three to five times this value, or 36 to 60 centistokes.

Once determined, this should be compared to the viscosity supplied by the selected lubricant.  Assuming the grease contains a 100 centistoke (ISO VG 100) oil, and the bearing is operating at 50°C, one can use a commonly available viscosity/temperature chart to determine the acceptability of the operating viscosity of the product in use.  Figure 2 illustrates this process.

Matching operating viscosity to bearing needs is the cornerstone of reliable lubrication.

As can be seen in the example, the suggested product would fulfill the optimum viscosity, delivering 60 centistokes at the stated temperature.  The product would function with a margin up to 65°C, and deliver the minimum allowable viscosity to 95°C. 

As long as the dynamic (operating) viscosity is above the minimum allowable viscosity, the use of EP agents is discouraged.  This example reflects why many electric motor lubricants are filled with wear resistance (AW) rather than seizure resistance (EP) agents and contain ISO 100 viscosity oils.

Viscosity selection for other bearing types and speeds follows this pattern.  The bearing’s maximum allowable operating speed and the limiting speed for grease lubrication (the point at which any given bearing should be oil lubricated) is determined by the bearing Pitch Line Velocity (PLV = mean bearing diameter times shaft speed = n*dM). 

Spherical and thrust bearings approaching a PLV of 150K, and ball and roller bearings approaching PVL values of 350K must be qualified for reliable operation with grease.

Choosing the Right NLGI Grade for Application Conditions

Grease stiffness influences grease performance in the bearing cavity.  The stiffer, or harder, the grease is, the less it will move within the housing once initial movement and settling have occurred.  There are nine grades of stiffness, as defined by the NLGI (National Lubricating Grease Institute).  The stiffness grades, and a parallel to a commonly recognized product, are shown in Figure 3.

Stiffness is a reflection of the amount of shear resistance that the grease presents to a weighted cone that is allowed to settle into a grease sample, as shown in Figure 4.  The rod that connects the cone to the instrument is also attached to a dial indicator at the top of the instrument. 

As the cone settles into the cup, the dial moves clockwise until movement stops. The number indicated by the dial is assigned to the grease as its stiffness value. The value correlates to the range of values on the NLGI Grade chart.

Assuming that the selection process has properly addressed the viscosity and additive type, selection of the grease grade (NLGI #1, #3, etc.) depends on bearing speed, temperature, vibration, shaft orientation, and application method.  Some general rules to follow:

1. Use #0, #1 for: Automatic systems with long distances, narrow feed lines, cold feed lines, significant number of 90°
2. Use #1 for: Outdoor single-point (low-pressure) applicators
3. Use #3 for: Vertical shaft axis applications.
4. Use #3 for: Very large bearings, high vibration conditions, very high-speed conditions, very high temperature conditions.
5. Use #2 for: Manual, battery powered, or air powered grease gun applications, moderate to low speeds, low vibration rates, and low heat load.

The majority of grease-fed components can be successfully serviced with #2 grade greases.   However, some circumstances warrant a change.  If the selected grease tends to show puddles of oil on the grease surface of unopened containers, then a step up in NLGI grade is appropriate.

If a bearing housing proves consistently difficult to purge, then consider moving to a softer grade.  If the bearing is subject to grease dilution or removal from frequent exposure to water, or wash down activities, consider a stiffer grade.

Calculating Initial Grease Fill and Replenishment Volumes

When an element bearing is first placed into service, the initial fill volume in the housing (if space permits) should be based on the volume needed to fill the base of the housing up to the bottom edge of an element sitting at the 6:00 position in the race.

If it is not feasible to observe the internal spaces in the housing, then a fill volume equal to 3X the replenishment volume of bearing for low-speed bearings, and 1X for high-speed bearings. In this instance, ultrasonic methods should be used to validate a proper oil film within 4 hours of initial operation.

Practical Formulas for Estimating Bearing Replenishment Volumes

There are two options for calculating the bearing net capacity and replenishment value. Schaeffler FAG bearings company provides an option to determine this as follows:

V = ((Pi/4) * W * (OD² – ID²) * 10^-9 – G/7800)*10⁶, where

V = volume in cubic centimeters,

OD = Bearing Outer Diameter, mm

ID = Bore Diameter, mm

W = Bearing Width, mm

G = Bearing weight, Kg

SKF bearing company provides an option to determine this volume as follows:

V = W * OD  * .005, where

V = volume in grams

OD = Bearing Outer Diameter, mm

W = Bearing Width, mm

From a practical perspective, the SKF approach offers greater flexibility in asset assessment when the exact bearing number (required for weight in Kg) is unavailable, making it the preferred method in LubeCoach calculations.

In addition to the grease introduced into the element spaces, enough grease should be placed into the housing to bring the grease level up to the lip of the outer race of the bearing.  When the excess from the initial fill is pushed away from the elements, it accumulates on the grease shelf at the race. It becomes a reservoir to continuously serve oil back to the raceway without crowding the elements.

A well-filled housing isn’t guesswork – it’s precision that feeds reliability.

The engineer/practitioner making these decisions has to know precisely which bearing by manufacturer number is in use to provide all the required values. Bearing manufacturer numbers are readily available at the time of initial installation and/or bearing replacement, so enough information is available for a correct initial fill.

Replenishment volumes: The bearing number details become fuzzy as repairs occur, CMMS systems are upgraded, and data is lost, and as the details from the original installation fade from memory. Therefore, it is necessary to have a more user-friendly approach to estimate replacement volumes for ‘in-situ’ applications.

One should consider both feed volume and feed interval since the two are interrelated. The formula shown in Figure 5 gives volumes in both grams (for metric dimensions) and ounces (for English dimensions) for three different interval ranges. 

Where actual bearing dimensions are not known, a close proximity to the actual suggested value could be estimated by using housing dimensions and factoring again by one-third {(D * B * .114) *.33}.

CAUTION: This provides only an approximation. For critical applications, the actual bearing make and model should be determined.

Excessive lubricant volume applied to bearings with labyrinth style seals and low pitch line velocity bearings (PLV ≤ 50,000 for ball and cylindrical roller, ≤ 30,000 for spherical and thrust roller) is not considered to be as problematic to the grease or bearing as it would be at higher speeds.

Excess grease dissipates readily, and any grease remaining in the working area has adequate transport time and space.  However, the same bearings with shields and plugged relief ports can accumulate grease residue. Over time, the residue can crowd the housing and cause churning and overheating. 

It is best to identify the precise bearing details for all relubrication volume and frequency calculations, and use the precise values to make well-defined decisions.

Grease Volume Guidelines for High-Speed Bearing Applications

The replacement volume for high pitch line velocity (PLV ≥ 330,000 for radial ball type; ≥ 150,000 for spherical roller and thrust type) element bearings requires thoughtful consideration due to shearing and heat produced by overfilling.  All bearings operating at high speeds benefit from more frequent but lower volume doses, emulating continuous replenishment that occurs with oil-lubricated elements.

At high speeds, it’s not about more grease – it’s about smaller, smarter doses.

For instance, the volume calculated for the short interval, Gq-Weekly, would ideally be uniformly distributed into the number of working hours for the period and applied accordingly. This technique would require automatic application, incorporating the use of timers and low-volume injectors or quality single-point lubricators.

Determining Optimal Grease Relubrication Intervals

The most dependable calculation for relubrication interval will be based on a combination of machine operating conditions and the expected grease service life for those conditions. Grease lifecycles can be predicted empirically.

Much like a bearing L₁₀ lifecycle value that indicates an operating interval for which 10% of a given bearing population would fail under identical operating conditions, the grease F_10Real value projects an operating interval for grease lifecycles and, consequently, relubrication intervals.

The F10 grease prediction model, as shown in Figure 6, is based on known grease degradation performance under test conditions, such as the FAG FE9 Tester (DIN 51821, Part 2), or similar test methods (SKF ROF Tester, DIN 51806).

The (theoretical) F_10Real formula for grease replenishment intervals, in hours, is shown in Figure 6.

Factor F₃ pertains to the actual operating temperature (given under T), and Factor F₄ pertains to the bearing load factor (given under P). Similar to the earlier comment about grease fill volumes, this approach works well when specific greases are being tested for specific applications during design considerations, but is difficult for the plant lubrication technician to apply to in-service components when the specific data points aren’t available.

When FE9 test data and F_10Real values for specific lubricant products are not available (it is typically not reported in OEM performance data), a modified approach can provide the reliability practitioner with a well-defined starting point. 

This empirically derived approach (formula shown in Figure 7) assumes applications where the actual load is a low percentage of net capacity, and where bearings are operating below the rated speed limits (Pitch line values are ≤ 300K for ball and roller type elements, ≤ 140K for spherical and thrust type elements).

In this approach, ‘K’ is the product of machine operating condition parameters, shown in Figure 8. The F₁₀ value is modified (hours to failure value is reduced) to allow equipment owners to factor in plant conditions.  Each of several factors becomes a judgment call, but with time and experience, results similar to the DIN 81825 calculation for net relubrication frequencies are achieved.

Where,

T_f = Time in hours between grease replenishment events

K = Product of environmental correction factors

N = Shaft speed

D = Bearing bore in millimeters

The correction factor, K, shown in Figure 8, allows the engineer to adjust frequencies based on machine operating and environmental considerations. The six provided conditions reflect practical issues that degrade bearing life and grease performance.

Figure 8 includes the correction factors for a 90 mm bore spherical roller bearing operating at 1200 rpm (PLV = 160,800) in direct exposure to rain and in a dusty environment, such as near an unpaved roadway and directly exposed to the weather. The calculated interval amounts to 18 days between relubrication events.

Multiple Bearing OEM Lubrication Guideline publications provide alternate quantitative approaches that are also valid and could be considered as a strong reference starting point.

Lubrication Practices for Single and Double Shielded Bearings

Key Differences Between Shields and Seals

Seals and shields perform similar functions in supporting an effective bearing lifecycle.  Shielded bearings may be used where no routine relubrication for the life of the machine is the design objective, but are typically used in housings where replenishment can be accomplished.  The key difference between sealed and shielded bearings is that shields are in contact with only one race, and seals contact both.

Grease Entry Paths in General Service Bearings

In general service bearing applications (pillow block, flange mount) grease may enter the raceway either from the face (axial feed) or from the outer perimeter of the bearing (radial feed).  Bearings are identified as radially fed in the OEM equipment catalog if they are serviced in this manner.

For instance, SKF identifies radial feed bearings with the W33 designation in the bearing number. Other bearing suppliers may use this or other nomenclature to differentiate between styles.  For bearings that are large enough that the housing is retained and only the element is replaced during a repair, the bearing will have an outer seal (lip or labyrinth type) at the outer periphery of the housing cavity.

Without a shield, gravity takes over – and so does premature grease failure.

It may or may not be equipped with a shield on the element itself.  The shield serves the function of metering grease and keeping contaminants out of the element area.  If the shield is missing from the element, then the grease slumps by gravity around the lower lip of the bearing and is drawn into the element gradually. This approach doesn’t prevent grease churning and premature loss of usefulness.

Configurations where the bearing and housing are replaced as a unit should contain shields on both faces.  Grease may enter axially or radially into the element pathway, and the shield in these instances is intended to vent pressure and prevent contamination entry.

Shield Orientation and Its Effect on Grease Flow

Electric motor bearing construction is highly user-specific.  If the user requests a shield or seal, then it can be supplied.  If the user doesn’t specify either, then it is the motor rebuilder’s or OEM’s prerogative to follow their advice. Unless the user specifically asks the question, he/she may not know.

Shield orientation is also user-driven.  The shield may face out or away from the windings. In these configurations, the annulus gap between the inner race and the shield performs a metering function, allowing grease to enter the raceway through the gap while in operation.

Shield direction shapes grease flow – and determines what stays cool and clean.

The grease also provides a baffle to prevent churning and heating of the grease away from the movement of the elements. It may also be configured with the shield facing toward the windings.  In these instances, the shield is thought to minimize the risk that the grease will enter the windings.

In both configurations, the gap between the lip of the shield and the inner face of the bearing ring is sufficiently open that fresh, viable grease is drawn into the raceway easily. The shield and gap can be seen in Figures 9 and 10.  Different installation arrangements can be seen in Figure 11.

Figure 10 provides a cross-sectional view of the element and races, and illustrates the gap in more detail.  The annulus is between 125 and 375 microns (0.005” and 0.015”). The shield also provides restraint of bulk contaminant flow into the raceway, but does not eliminate contamination problems.

Given that the dynamic element to race clearances ranges between 0.5 and 1.5 microns, it is clear that particulates that can corrupt the dynamic oil film can readily pass into the race area.

Installation Considerations for Shielded Bearings

Figure 11 (below) demonstrates accepted mounting techniques for shielded bearings in electric motor housings.  (Original Graphic Ref., Heinz Bloch, “Practical Lubrication for Industrial Facilities”). Single shield bearings may be installed such that the shield is facing the grease supply, or is on the opposite side of the bearing receiving grease supply.

When installed facing the flow of grease, the shield can behave as a baffle to limit the flow of grease, if the grease volume is not overpowering, and minimize the risk of churning.  Unfortunately, if grease is supplied under too much force (high pressure or volume), the shield may collapse into the raceway and compromise the bearing.  It is important to know which configuration exists, if possible, before proceeding with the lubrication event. 

There is no single position taken by bearing manufacturers for the use of shields and seals (single or double shield configurations).  Machine manufacturers select seals and shields when contamination from the environment is expected. Shields are also prevalent on electric motor applications. 

The shield is beneficial to prevent grease churning in the housing, but does not prevent the movement of the grease toward the center of the motor. The motor owner should be aware of the options provided by the builder and should publish and provide technical specifications according to what is believed to be best for the production site.

Best Practices for Initial Bearing Grease Fills

The initial fill for a single shielded bearing should conform to the advice provided above under open face bearings.  OEMs do not differentiate between fill and replenishment practices based on the bearing component or seal configuration. 

The quantity of grease to be placed into the bearing at the time of installation is governed by the vacant space within the bearing.  The quantity of grease for the housing is not definable because a bearing can be fitted to multiple bearing housings.  Bearings are shipped with a quantity of grease that serves as both a corrosion inhibitor and an initial charge for operation.

Any addition of grease via hand-packing before mounting the bearing should be conducted under clean room conditions with dust-free/lint-free gloves.  Even slight handling of element bearings can induce corrosion.

As noted previously, when a bearing is placed into a housing, it is necessary to create a grease floor in the housing that is flush with the outer race lip at the bottom of the housing.  This will allow any new grease to slump to the area at the bottom of the shield/open face and provide a renewing reservoir. 

Guidelines for Relubricating Shielded Bearings

The volume for replenishment is determined by the formulas provided above. The advice is based on bearing size and speed, grease longevity, and operating conditions.  Technicians should be aware of the use of shielded bearings and whether the shield faces the grease flow or is on the opposite side of the bearing.

Shielded bearings should be lubricated while the bearing is running to prevent overpressurization of the seal and possible collapse into the bearing pathway.  Movement of the elements during lubrication will cause the grease to draw into the element pathway for maximum flushing and distribution effectiveness.

Greasing on the run keeps pressure down and distribution up.

Bearings should not be greased while idle if possible.  Where this is necessary, the equipment owner must determine the minimal acceptable amount of grease for the installation and its operating conditions, and restrain grease addition to this value only to avoid collapsing the shield.

Short of physical observation of the immediate area at the bearing (which is not possible without disassembly of the housing/machine), it is not possible to know the pathway that the grease follows once it is in the housing. 

Understanding and Maintaining Sealed-for-Life Bearings

Within the last few years, there has been a marked increase in the dependence on sealed for life bearings for a wide variety of commercial, residential, and even some industrial machines.  The concept ‘sealed for life’ reflects the design goal, not the expected operational period.  ‘Sealed for life’ is also not a guarantee of operational performance. Sealed for life bearing applications have grown from the traditional deep groove ball bearing to include all shapes, sizes, and design parameters.

Equipment manufacturers’ primary determining factor for whether to choose a seal (not to be replenished while in use), a shield, or neither is driven by machine lifecycle cost and duration requirements.  For typical components where sealed bearings are widely or singularly used, the component supplier has concluded that the likelihood of achieving the required lifecycle is better if the component is not relubricated.

Figure 12. Sealed Bearing Configuration

Sealed bearing lifecycles are greatly influenced by the in-use grease condition, which is itself influenced by the seal condition (leakage and contaminant exclusion). The significant improvements seen in both grease and seal materials have enabled machine manufacturers to design for and achieve longer lifecycles with sealed bearings in progressively more challenging conditions.

Favorable conditions for sealed bearings could include:

• Small bearing dimensions
• Low shaft rotational speeds
• Low shaft circumferential speeds
• Low loads
• Clean conditions (no moisture, no dust)
• Low heat
• Short expected lifecycles

As the relative load, surface contact speed, temperature, and contaminant load increase dependence on shielded or open face relubricatable bearings increases. Sealed bearings are not intended to be relubricated during the machine’s expected lifecycle.

However, shielded bearings are configured for and are expected to be replenished at some interval.  Elastomeric radial lip seals are designed primarily to retain the lubricant and are only marginally expected to prevent external contaminant ingression.

Seals are capable of containing both liquids and semi-solids, are capable of operating in bearing sumps varying from -60 to 200°C, can operate with peripheral speeds up to 20 m/s, and support pressures between 20 and 100 kPa (2.9 to 14.5 PSI).  Seal radial loading is determined by the types of elastomers used, the contact area of the seal on the race surface, internal pressure from the fluid, and spring tension.

Every turn of the shaft turns the seal into a precision fluid pump.

As the shaft turns, the movement of the shaft causes the seal to flex. This provides a subtle pumping motion that serves to push the fluid toward its reservoir area. The fluid creates a film barrier between 0.125 mm and 1.25 mm wide. Lip contact load is a key performance factor.

Contact load ranges between 0.05 and 0.12 N/mm (0.3 to 0.7 lb/in) of circumference. As the lip load (spring tension) increases, the surface temperature rises in relation to shaft speed. Since temperature is a prime cause of seal failure, lip loads should be as low as possible and still maintain a seal. Figure 12 provides a look at the key features of a lip seal.

Key Takeaways for Effective Grease Relubrication

Grease relubrication practices should be handled with care.  Precise grease volumes and carefully calculated intervals will help the reliability professional reduce outages, reduce costs, improve machine performance, and enjoy a less stressful career.   The formulas provided above are either directly or indirectly associated with bearing supplier recommendations.

The LubeCoach recommendations reflect the principles noted in the formulas provided. These may be programmed into a worksheet with minimal effort.  The LubeCoach is designed to offer insights without requiring complex spreadsheet construction. Learn more about LubeCoach Circular Bearing Lubrication Calculators.

References

Con GMBH, Bearing lubrication Calculation Worksheet, FAG Bearings, German Society of Tribology, others.

FAG Bearings Limited, Roller Bearing Lubrication Guide, Publication Number WL 81 115/4 EC/ED

LubCon USA, LubCon GMBH, Bearing Lubrication Calculation Worksheet,

FAG Roller Bearing Lubrication Guideline WL81115E.

Machinery Lubrication magazine

Web Reference X.X – Timken Bearing Company

Web Reference X.X – SKF Bearing Company. http://mapro.skf.com.

Snyder, D.R “Sealed-for-Life Bearings: To Relubricate or Not?” Tribology and Lubrication Technology, December 2004. Pages 33 to 40.

Booser, R.E., Tribology Data Handbook, Chapter 14, Dynamic Seals.  CRC Press

Hodowanec, M.M., “Evaluation of Anti-Friction Bearing Lubrication Methods on Motor Life Cycle Cost”. Siemens Industry and Automation Incorporated. 0-7803-4785-4/98.  IEEE. 

It would be overly optimistic or even a bit naïve to assume that all lubrication-related design decisions made by the equipment manufacturer best serve the end-user’s long-term interests. Understandably, cost competitiveness will have been foremost on the manufacturer’s mind. After all, many machines are continuing to be purchased with initial cost as the primary (if not only) criterion. These machines are candidates for upgrading.

A modest upgrade today can prevent a cascade of costly failures tomorrow.

Paying a small incremental added charge for an upgrade makes far more sense than upgrading after many repeat failures. Upgrading at the specification stage is possible if the writer of the spec is knowledgeable. That’s important. Knowledge is a quality that builds up; lack of knowledge leads to decay in every sense of the word.

What Causes Lubricants to Degrade

Upgrading to superior lubricants, protecting lubricants from premature degradation, and improving the method by which lubricants are delivered to bearings is often feasible and desirable. Occasionally, “naysayers” argue that lubricants never wear out, but they’re wrong.

Lubricants can suffer from gradual depletion of additives, contamination, or the effects of excessive temperatures. Water causes partitioning, essentially a separation of molecules from certain beneficial additives. Water and dust particles combine to form sludge. Common sense tells us that issues with lubricants can render the fluid unserviceable to the point of initiating catastrophic machine failures.

When Manufacturers’ Standards Aren’t Enough

Experience also indicates that manufacturers are satisfied if, in their view, “traditional” maintenance frequencies or intensities are carried out. Similarly, a vendor-manufacturer may be satisfied if, of the 100 machines delivered to their Customer X, only 95 are reaching the industry average life of, say, three operating years. Thus, in this hypothetical case, out of every 100 machines, five would experience avoidable failures within this time.

Even a small percentage of avoidable failures can drain a maintenance budget fast.

But suppose that, in this arbitrary example, Customer Y has all 100 of his machines exceed the industry average, and they operate for three years before one of them needs a repair. In that case, Customer X will spend money on repairs while Customer Y has no such expenses or outlays. Chances are that Customer Y is more successful because it implemented suitable upgrades, and Customer X should consider upgrading.

Consider this our way of claiming that our text deals with eliminating the 5% of “elusive” repeat failures. Arguing that traditional methods and practices still suffice is a bit like pointing out that people can still get from one place to another in a 1915 Model T Ford automobile.

While agreeing with that statement, we would have no difficulty explaining and accepting that a 2021 mid-size Ford automobile will better serve our low-maintenance cost and high-reliability goals.

Elusive pump failures are, in all probability, consuming a disproportionate amount of the maintenance budget. Years ago, the author compiled statistics that placed from 7% to 10% of a facility’s process pumps in the frequent failure (or “bad actor”) category. Typically, approximately 60% of the maintenance budget for equipment category process pumps is consumed by the 7% to 10% low-performing population.

Cost-Justifying Upgrades

An empirical assessment makes the conservative assumption that a simple available upgrade measure will extend safe operating life by factors ranging from 1.1 to 1.4, that implementing two available upgrade measures would extend safe operating life by factors from perhaps 1.5 to 2.5, and that three low-cost improvement measures would move pump operating lives to multipliers in the range from 2.6 to roughly 3.3.

These approximations are often used in initial cost justification calculations; they have usually yielded reasonably close results. Proceeding with upgrade plans is considered justified if payback is obtained within 18 or fewer months.

The right upgrades can double or even triple a machine’s operating life.

Another rule of thumb uses an exponential approach. That rule states that if a fully upgraded machine has a reliability of 1.0, then one missed upgrade will lower the reliability to 90% of 1.0 = 0.9; two missed upgrades to 90% of 0.9 = 0.81; three missed upgrades to 90% of 0.81 = 0.73; four missed upgrades to 90% of 0.73, equaling only 0.66, and so forth.

We consider this elementary rule of thumb rather optimistic. Actual achieved reliability with four deficiencies is probably less than 50% of what would be achievable with better bearings, better mechanical seals, better couplings, better constant level lubricators, or whatever other upgrades are available and within reach.

Then, there is a third rule of thumb worth sharing. Again, a reasonable assumption is made; a probable 20% improvement in failure avoidance, or repair cost reductions, or life extension is thought to result from each upgrade. In that case, an upgrade will move the equipment reliability from 1.0 to 1.2; a second (different) upgrade would capture 1.22 = 1.44; further upgrades would be 1.23 = 1.73, and 1.24 = 2.07.

The implementation of four proven upgrade measures would cause the MTBR (mean time between repairs) to be extended slightly beyond twofold. Yearly repair expenditures would be one-half of what they were before; workers previously laboring on repairs would now spend time on repair avoidance tasks. Safety would improve, community goodwill would be boosted, and worker morale would also increase.

Turning Calculations Into Action Plans

Making good use of shortcut calculations is encouraged by a good management team. Good managers routinely ask responsible staffers to accept responsibility for cost justification and advocacy of reliability improvements that yield rapid payback. These employees would be encouraged to become familiar with the above three reasonably accurate shortcut calculations. In turn, these employees would accept the task of engaging in 12 management-sponsored actions and pursuits:

1. Define equipment operating capability (reliability) limits to prevent lubrication-related failures adequately.
2. Develop lubrication strategies sufficient to maintain equipment operation and availability within specified limits.
3. Prioritize detection of limit deviation and definition of response criteria according to known or anticipated failure intervals and consequences.
4. Enforce and own the policy and procedures for lubrication-related reliability-limit changes.
5. Document the approval of new and changes to existing lubrication-related reliability limits.
6. Establish lube-application-related limit documentation and ascertain access capabilities to retain lubricant performance limit, its purpose, and its history.
7. Set expectations for upgrading equipment assigned to limit monitoring points and assist in creating effective contingency plans for maintenance deviations.
8. Track and monitor limit compliance by contractors and the end-user company’s personnel.
9. Investigate chronic limit deviations to detect and address potential constraints that might degrade business value.
10. Communicate program performance measures on a routine basis (percent in control, chronic limit deviations).
11. Reconcile lubricant-limit performance against turnaround maintenance inspection results.
12. Audit reliability-limit database integrity.

Why Strategic Upgrades Pay Off Long-Term

We have learned that best-in-class companies have institutionalized the study and dissemination of best-practice lubrication details. But we have also learned that the decision to upgrade one’s method of lube application often depends on the equipment manufacturers’ input. Likewise, the decisions are at least influenced by the ranking that experienced users assign to these applications.

Lubrication Strategies and Tips: How to “Kick-start” Any Lubrication Program

Lubrication Strategies and Tips is a full-color practical and comprehensive quick- guide designed to help and empower lubrication, maintenance and reliability personnel to quickly navigate the complexities of industrial lubrication and put together with confidence and understanding, a winning lubrication management program.

A Most Practical Approach to Lubrication Excellence

Authored by Kenneth E. Bannister, a world-renowned author and expert in industrial lubrication and asset management, this book addresses how to quickly turnaround or fast-track a winning and effective lubrication  management program focused on equipment reliability, operational efficiency, and cost reduction.

Structured into eight focused, easy-to-read chapters, each one addresses specific challenges and opportunities in the practical lubrication of machine assets. Whether you’re starting from scratch or looking to enhance existing practices, this guide provides actionable tips and proven strategies that serve as springboards for immediate success in your lubrication efforts.

Proven Strategies from Real-World Experience

Drawing from over three decades of hands-on experience across diverse industries, Kenneth E. Bannister shares field-tested strategies and tips that have consistently delivered outstanding results. These insights are presented in a clear, easy-to-understand format to ensure you can apply them directly and effectively within your organization.

Focused Chapters for Maximum Impact

Each chapter is carefully crafted to target critical areas known to deliver the greatest success when implemented, including:

• Lubrication program/system design
• Lubrication management
• Lubricant receiving and storage
• Lubricant application and operation
• Contamination avoidance
• Predictive testing
• Weather strategies
• Lubrication Safety

Your Companion for Lubrication Success

Lubrication Strategies and Tips is more than just a book – it’s a trusted companion designed to empower you with practical knowledge and expert guidance. It equips you to develop and implement a best-practice lubrication management program that enhances equipment reliability, reduces downtime, and maximizes operational efficiency.

Who Should Read This Book?

This book is ideal for:

• Maintenance Technicians and Lubrication Specialists – Seeking practical tips for daily lubrication tasks.
• Reliability Engineers and Asset Managers – Aiming to optimize lubrication programs and equipment performance.
• Maintenance Managers and Supervisors – Looking to implement effective lubrication strategies that reduce costs.
• Students and Educators – In industrial maintenance and engineering programs focused on lubrication best practices.

Achieve Lubrication Excellence

With clear explanations, actionable insights, and proven strategies, this guide empowers you to take control of your lubrication program and achieve operational excellence. “Kick-start” your lubrication success today with practical, reliable guidance from one of the industry’s most respected experts.

Available at River Publishers.

What is Lubrication?

Lubrication is the process of reducing friction, wear, and heat between moving surfaces by introducing a lubricating substance, such as oil or grease.

The Purpose of Lubrication

If you walk into any industrial facility, you will find lubricants. While they come in all types of textures (greases or oils), viscosities, and packaging, one thing remains true: We need them. Lubricants were designed to reduce friction as their main function. However, that’s not their only use.

Although lubricants can effectively reduce friction, they can also reduce or transfer the heat built up in machines.

Although lubricants can effectively reduce friction, they can also reduce or transfer the heat built up in machines. This only applies to oils circulated through the systems and not grease that remains in place.

Additionally, lubricants can minimize wear by providing an adequate film to separate surfaces from rubbing on each other.

Lubricants also help improve the efficiency of the machine by removing heat and reducing friction. They can also remove contaminants (for oils that are circulating, not grease) and transport them away from the machine’s internals. This is due to some additive technologies (such as dispersants or detergents).

Depending on the type of lubricant or its application, its function can also change. For instance, hydraulic oils are specifically used to transmit power, something that gear oils or motor oils cannot do. On the other hand, the lubricant can be considered a conduit of information if condition monitoring is considered.

Lubricants provide several functions depending on their application and environment. However, the main functions of a lubricant include reducing friction and wear, distributing heat, removing contaminants, and improving efficiency.

How Lubrication Reduces Friction and Wear

At the heart of lubrication is the main function of overcoming friction. When two parts move or two surfaces rub against each other, microscopic projections called asperities exist. Even on what appears to be smooth surfaces, asperities exist, and when these move over each other, friction is produced, which in turn can generate heat and cause wear.

Wear can typically occur in various forms, but in many of these, the touching of the asperities serves as the trigger point for wear to occur.

This is where lubricants really make a statement. They serve to provide a barrier between the two surfaces, almost allowing them to float over each other seamlessly. As such, friction is reduced once the asperities are kept apart, and this even influences a reduction in the occurrence of wear.

Wear can typically occur in various forms, but in many of these, the touching of the asperities serves as the trigger point for wear to occur. With the presence of the appropriate viscosity of lubricants, these asperities can be kept apart, and the occurrence of wear can be diminished significantly.

The Role of Lubrication in Preventive Maintenance

As we have noted above, proper lubrication can help to prevent wear. This is one of the many characteristics which make it ideally suited as a tool for preventive maintenance.

As defined, preventive maintenance can help maintenance professionals schedule time-based tasks / prescribed intervals¹. Any maintenance manual will include prescribed intervals at which lubricants should be changed (typically after 500 hours or 5000km).

OEMs (Original Equipment Manufacturers) defined these intervals as general guidelines for machine operators. This gives operators an idea of the lubricant’s expected life or the duration after which it would no longer be able to perform its functions adequately. By changing the lubricants at these intervals, one could avoid unplanned downtime.

Another aspect of lubrication associated with preventive maintenance is relubrication intervals. In some machines, there are minimum required reservoir levels that need to be maintained.

However, depending on the system, there may be some expected loss of lubricants during its lifetime. As such, relubrication intervals can help prevent unwanted downtime by injecting new oil or grease (with fresh additives) and maintaining the required reservoir levels.

Types of Lubricants and Their Applications

Not all lubricants are created equally! In fact, they need to be designed differently for the various applications in which they are to be used. Typically, the overarching classification of lubricants can fall under either oil or grease. However, there are further categorizations that also include solid lubricants and specialty lubricants, as there are many varying applications of lubricants.

Oil Lubricants: Characteristics and Uses

Most of us are very familiar with oils. They are liquid; we use them in our cars or trucks, but what are they? An oil is comprised of base oil and additives. The additives can be used to either enhance, suppress, or add new characteristics to the base oils².

Typically, oils can be used in many different applications and provide the advantages of having various viscosities according to the application³. These can range from oils with a viscosity similar to that of water to oils as thick as tar.

One of the main advantages of using oils as lubricants is their ability to dissipate heat from the system. Since they are fluid and circulate, they can “move” heat away from specific components and even help to remove some contaminants.

Oils can be used in gasoline-engine passenger cars, diesel-engine applications, circulating systems, turbines, gear applications, hydraulics, compressors, or even natural gas engines. Each application represents a different ratio of additives to base oils, ranging from 30% (motor oils) to a mere 1% additive (turbine oils).

Grease Lubricants: Advantages and Limitations

While the industry is familiar with oils as lubricants, there are some places where grease works better than oils! Greases are oils to which a thickener has been added. As such, they comprise base oil, additives, and thickener. The thickener holds the oil in place, allowing it to perform its main functions of reducing friction and providing lubrication.

One of the main advantages of greases is their ability to stay in one place. Consider a bearing placed at a 90° or 180° angle. If oil were used to lubricate this, it would drain out very easily. However, grease stays in place and still ensures that lubrication occurs.

While staying in place is a major advantage of grease, there are also some disadvantages to using it. A couple of those include the fact that grease cannot transfer heat away from components and keeps contaminants in place. These can both negatively impact the equipment.

Similar to oil, grease has different viscosities as per the NLGI (National Lubricating Grease Institute). These range from a 000 (almost the consistency of oil) to a 6 (similar to that of a block) and are all made for varying applications, as shown in the figure below.

While these viscosities define the application, one must also remember that the base oil viscosity can also differ. As such, operators must be mindful of NLGI grade, base oil viscosity, and additive package when selecting an appropriate grease.

Solid Lubricants: When and Why to Use Them

Why do we need a solid lubricant if we already have oils and greases in different states? Particular applications make these lubricants mandatory as they are the only ones that can meet the conditions and specifications involved.

Unlike oils or greases, these solid lubricants are designed to work in one lubrication regime, boundary lubrication⁴ (more on this later in the article). What sets these lubricants apart is their ability to form very thin films on the surfaces of moving components, which reduces friction due to their very low shear strength.

Some examples of solid lubricants include graphite, Molybdenum Disulfide (MoS2), Boren Nitride, and Fluoropolymer (PTFE). These solid lubricants can usually be used as grease additives (such as MoS2 for greases in mining with high load, low-speed applications) or even in the space industry for dry lubricant coatings on spacecraft.

Lubrication Regimes: Understanding the Science of Lubrication

The primary purpose of lubrication is to create an acceptable lubricant film to sufficiently keep the two moving surfaces apart while allowing them to move with reduced friction. This is the ideal condition, but a lubricant can undergo a couple of different regimes before it achieves this full film format.

The figure below shows the overall relationship between film thickness and the related regime and the associated regime relationships with the coefficient of friction.

Boundary Lubrication

At startup or rest, lubricants are usually residing in the sump. For this example, let us think about a car at rest. Since the vehicle has not moved, all the oil should have been drained and settled in its sump at the bottom of the engine. When the car starts, all the parts on the inside will begin moving.

Only after it starts does the oil begin its swift journey from the bottom of the sump to all the moving parts. That means that there is a delay between the oil getting to perform its function or reaching the moving parts.

In boundary lubrication, the oil has not fully formed its film, and there isn’t adequate separation of the asperities.

During boundary lubrication, the oil has not fully formed its film, and there isn’t adequate separation of the asperities. In this state, wear can still occur, and it is in this state that most wear occurs. A similar situation occurs during equipment shutdown, where the components also experience this boundary state of lubrication.

The figure below shows the various film conditions. In boundary lubrication (c), the asperities touch, whereas they are fully separated in (a).

Surface-active additives are critical for boundary lubrication and become activated under certain conditions. One of the most popular additives is EP (Extreme pressure) additives, which become activated when temperatures are increased (usually as a result of increased friction).

A surface film is typically formed during boundary lubrication. This can be the result of physical adsorption (physisorption), Chemical adsorption, or Chemical reactions involving or not involving stearate.

Physical adsorption occurs under mild sliding conditions with light loads and low temperatures. Chemical adsorption (chemisorption), stronger than physisorption, occurs when fatty acids react with metals to form soaps, which may or may not be attached to the surface.

On the other hand, chemical reactions that do not involve a substrate allow for slightly stronger bonds than chemisorption. However, with phosphorus-containing compounds, the phosphorus exists in a soluble carrier molecule that degrades at elevated temperatures, plates out on the metal surfaces, and forms a phosphorus soap (typically found in the Antiwear additive packages).

The last and strongest bonds to protect the surface are the chemical reactions involving a substrate where sulfide layers are formed on the surface. These provide low friction and good adhesive wear resistance⁵.

Mixed Lubrication

This state of lubrication exists as the lubricant transitions between Boundary and Full-Film lubrication. Its average film thickness is less than 1 but greater than 0.01μm. Some exposed asperities and roller element bearings can still experience this state during their start-stop cycles or if they are experiencing excessive or shock loads. These thin films are exposed to high shear conditions, leading to increased temperatures and reducing the lubricants’ viscosity⁶.

During this state, antiwear and EP additives protect the surfaces (similar to boundary lubrication). Most lubricants transition through this phase, and the additive packages must be able to help protect the surfaces.

Hydrodynamic Lubrication

During this regime, the two surfaces are usually fully separated. They are thick hydrodynamic fluid films that tend to be more than 0.001 inches (25μm) in depth, experiencing pressures between 50-300psi⁷. Ideally, friction only results from the shearing forces of a viscous lubricant⁸.

In this state, the surfaces are conformal, meaning that the angles between the intersecting surfaces remain unchanged. It is important to remember this, as it differentiates the hydrodynamic regime from the elastohydrodynamic regime. As shown in the figure below, the coefficient of friction changes for the various regimes, with the hydrodynamic regime having the lowest value.

Elastohydrodynamic Lubrication (EHL)

One of the main defining factors with EHL is that the oil’s viscosity must increase as the pressure on the oil increases, such that a supporting film must be established at the very high-pressure contact areas. Due to the pressure of the lubricant, elastic deformation of the two surfaces in contact will occur. These films are thin, typically around 10-50 μinches (0.25 – 1.25μm).

The surfaces in EHL are non-conformal (unlike Hydrodynamic lubrication), and the asperities of the contacting surfaces do not touch. However, the high pressures can deform either of the contacting surfaces to ensure that a full fluid film is maintained. This can increase the coefficient of friction.

Common Lubrication Mistakes and How to Avoid Them

Mistakes can happen all the time, but when we repeat them, they can become a habit or, worse, be viewed as a “best practice” within our industry. In the lubrication realm, there are a few common mistakes that occur quite frequently. In some cases, the operators may not understand or be aware of the full gravity of these mistakes. In this section, we will explore ways to avoid these mistakes.

Over-Lubrication vs. Under-Lubrication

“Some grease is better than no grease” is a common saying in the industry. However, there is such a thing as over-lubrication! Think about swimming pools. The pool usually has different levels: a minimum fill level, then a mid-tier level, and finally, the maximum level.

If we don’t fill it to the minimum level, it’s basically a puddle of water, not a swimming pool. We need a certain volume of water to function as a swimming pool. The same applies to our equipment.

We will under-lubricate our equipment if we do not provide enough grease or oil. In these cases, there is not enough lubricant to form the full required film to keep the two moving surfaces apart and perform all the lubricant functions. Therefore, there will be increased friction, wear, and heat, all leading to system inefficiencies.

On the other hand, if we filled the swimming pool beyond the maximum level, it would be pretty tricky for us to stand in it (while touching the bottom) or walk across the length of the pool without having lots of opposition from the water compared to walking across the length of the pool when it’s filled mid-way.

Something similar is happening with our equipment. If we over-lubricate it, we place additional stress on the components to perform extra work, as they must move on a thicker layer of lubricant, which will cause frictional losses. This can cause the equipment to heat up, leading to degradation of the lubricant and loss of efficiency.

Both over-lubrication and under-lubrication can be detrimental to your equipment. Instead, use the optimal level of lubricant, or (in the case of greases) use ultrasound to determine the required amount of grease for your application. In both cases, the ideal amount of lubricant is the volume at which the coefficient of friction is significantly lowered.

Choosing the Wrong Lubricant for the Application

Quite often, the wrong lubricant is chosen for the application. This can happen in several ways, whether unintentional or an error passed down through shift changes. Selecting the correct lubricant for your application begins with knowing the environmental and operational conditions and the equipment specifications.

Your first guide/resource should be the equipment’s OEM. They designed the equipment to perform within specific tolerance limits and can advise on the most appropriate lubricant given these tolerances. If they cannot be contacted, an alternative would be contacting your lubricant supplier to help determine the best lubricant based on their expertise with similar types of equipment in varying conditions.

Selecting the correct lubricant for your application begins with knowing the environmental and operational conditions and the equipment specifications.

Another misconception about selecting lubricants is that they should be chosen based on their initial cost. Instead, the total lifecycle cost of the lubricant should be considered, and the properties of the lubricant should also be factored into the decision-making process. The initial cost of the lubricant pales compared to the cost associated with unplanned downtimes, the short life span of the lubricant, and its disposal.

Inadequate Lubricant Storage and Handling

Lubricants should be handled with care. They can be affected by temperature, light, water, particulate, or even atmospheric contamination. They must be stored properly in a dry, clean, cool space (not exposed to the elements).

When transferring lubricants from larger containers into smaller ones, think of how you would perform this operation if you transferred blood from the blood bank to one of your family members. Would you use any container you found on the ground, or would you ensure that it is a sterilized container (needle or equipment)?

Lubricants can easily become contaminated with particulates, which can then be transferred to machines, leading to unplanned shutdowns. When transferring lubricants, it is critical to ensure that we do not introduce contaminants or transfer these contaminants to our equipment. We must keep the lubricants clean and free from contaminants.

Ignoring Environmental and Operational Conditions

Not all lubricants are created equally. Some are designed for harsher environments, while others can only function in regular operating conditions. Mineral oils can typically work in many circumstances. However, when higher temperatures or loads are involved, this may be a job more suited for a synthetic lubricant.

On the other hand, if the lubricants are geographically close to waterways or come into contact with them in any way, then these should be environmentally acceptable lubricants (EALs). Depending on the load and temperatures experienced by your equipment, your lubricant provider or OEM for the machinery can advise on the best-suited lubricant that will perform in these conditions.

Lubrication Maintenance Best Practices

We’ve already covered some mistakes; it’s time to look forward to some lubrication best practices. To some of us, these may seem trivial, but they can lead to big impacts on your overall maintenance budget and can even manage to decrease some unplanned downtime.

Creating a Lubrication Maintenance Schedule

Every component in your industrial facility needs to be lubricated. The frequency at which this occurs, alongside the type of lubricant, can vary greatly. However, by properly mapping out your lubrication points and frequency intervals, you can develop a lubrication maintenance schedule that your planner will be proud of!

The first task on your list would be to have a detailed listing of all your assets, their locations, the type of lubricant being used, and suggested relubrication frequency. Next, this can be consolidated into daily, weekly, monthly, and quarterly tasks.

Afterward, you must bring your mapping skills into place as you incorporate the lubrication tasks with other maintenance tasks in the same area. This way, your assigned personnel maximize their time in one geographical location.

Importance of Lubricant Analysis and Condition Monitoring

How often do you perform blood work for yourself or visit your doctor? Performing blood work is similar to taking an oil sample for our equipment as we investigate what’s happening inside it. This can give us a heads-up on an impending failure (if there is a high wear metal concentration or the presence of contaminants) or an issue in the oil (changes in viscosity or additive packages).

By effectively monitoring the health of your oil, you can prevent unplanned shutdowns or even extend its life. This can save your company from significant losses and increase your production output.

Lubrication Training for Maintenance Teams

Quite often in our industry, we hear, “Oil is oil, or grease is grease,” but after reading this article, I’m sure you will agree that those words are a very big misrepresentation. This is why training is so important for our teams. We want to ensure we all understand why we’re not leaving the oil drums out in the rain and pouring them into our equipment!

This will lead to water getting into the oil drums. Then, we include the water in our equipment alongside our oil, which will change the oil’s viscosity, possibly leech out some of the additives being used for protection, and can act as a catalyst for further, rapid degradation of the oil.

This simple storage and handling concept can cost our company unplanned downtime and loss to production, but by adequately training our teams to understand lubrication and some of the best practices, we can transform our facilities into world-class lubrication sites. The only way to do this is as a team working together to achieve a goal that we all understand.

Frequently Asked Questions About Lubrication

How Often Should Equipment Be Lubricated?

This can change depending on your environment and operating conditions. A machine operating in a clean environment with ambient temperatures and a typical load should be lubricated according to its schedule. However, if this same machine is in a dusty, high-temperature environment working 24/7, its change or relubrication intervals will be shorter than the regular ones.

Lubrication reduces friction in your system. Hence, you can detect when friction levels increase if you’re monitoring your assets using ultrasound. This would allow you to apply a small volume of lubricant to lower these levels. (This is specifically for greases.)

You are always advised to check with your OEM, who will have recommended lubrication schedules for your equipment in varying environments and operating conditions.

What Are the Signs of Poor Lubrication?

Poor lubrication can mean under- or over-lubricated assets or incorrect use of a lubricant in a particular application. If your lubricant is not meeting the expected intervals and the components constantly fail due to lubrication issues, these are some telltale signs of poor lubrication.

How Do I Know If I’m Using the Right Lubricant?

All lubricants are required to meet standards to prove their performance, or OEMs may approve some for their suited applications. The lubricant’s performance standards should be compared to those outlined by the OEM for a particular piece of equipment. If they don’t match or there are discrepancies, then the OEM or lubricant supplier should be contacted for verification. Sometimes, an over-qualified lubricant may be used in your application, and it can also give you the expected results, but of course, at a higher cost.

Lubricants are the lifeblood of our equipment and keep our industry moving. We need to understand them fully, their roles in our equipment, and how we can optimize them for maximum performance.

References

1. Debshaw, B. (2023, February 02). Reducing Costs, Increasing Production: The Remarkable Impact of Predictive Maintenance. Retrieved from Precision Lubrication Magazine: https://precisionlubrication.com/articles/predictive-maintenance/
2. Mathura, S. (2024, April 01). Lubricant Additives: A Comprehensive Guide. Retrieved from Precision Lubrication Magazine: https://precisionlubrication.com/articles/lubricant-additives/
3. Mathura, S. (2023, March 26). Oil viscosity: A practical guide. Retrieved from Precision Lubrication Magazine: https://precisionlubrication.com/articles/oil-viscosity/
4. Britton, R. (2023, January 26). How do Solid Lubricants work? Retrieved from Precision Lubrication Magazine: https://precisionlubrication.com/articles/solid-lubricants/
5. Hamrock, B. J., Schmid, S. R., & Jacobson, B. O. (2004). Fundamentals of Fluid Film Lubrication Second Edition. New York: Marcel Dekker Inc.
6. Pirro, D. M., Webster, M., & Daschner, E. (2016). Lubrication Fundamentals, Third Edition, Revised and Expanded. Boca Raton: CRC Press.
7. Pirro, D. M., Webster, M., & Daschner, E. (2016). Lubrication Fundamentals, Third Edition, Revised and Expanded. Boca Raton: CRC Press.
8. Hamrock, B. J., Schmid, S. R., & Jacobson, B. O. (2004). Fundamentals of Fluid Film Lubrication Second Edition. New York: Marcel Dekker Inc.

When we walk into a pharmacy, there are thousands of items. Some of them do the same job but have different names and price points, while others are specialty items designed to solve a particular problem at a slightly elevated price point. Some of these may not be readily available in all pharmacies. Machinery lubricants adopt a similar type of pattern.

There are various OEMs on the market that all produce finished lubricants. Some of the majors are Shell lubricants, ExxonMobil, Total, and Castrol, while there are other niche producers who handle very specific markets. Like the pharmacy, where numerous choices solve the same issue, we have machinery lubricants from different suppliers who meet most of the standard specifications or specialty-grade products.

Each supplier will have a proprietary blend that comes from an invested amount of Research and Development into their product to produce something that meets international equipment specifications and regulatory standards.

Does this mean that one product is better than the other, or does it mean that all hydraulic oils (for instance) are the same? This depends on the application.

The hydraulic oil used to top up the compactor of a garbage truck with several leaks will not be the same hydraulic oil that we use for a critical hydraulic system in a power plant, which requires fire-resistant oil. We can also compare the engine oil used for a 40-year-old regular car to that of the engine oil used in a McLaren race car on race day.

Different applications have varying risks associated with them, as well as performance expectations; this is what sets certain lubricants apart.  

The 5S Methodology

While some may be familiar with the 5S methodology of lean principles, this may be the first time others have heard of its existence. In essence, these principles help to maintain quality standards within the workplace. As per (ASQ, 2024), 5S is a quality tool derived from 5 Japanese terms used to create a workplace suited for visual control and lean production. The 5 pillars and their translations are listed in Table 1 below.

We can use these principles to adopt a leaner approach to lubricant consolidation in our facilities. This way, we ensure that our operators have a clean, manageable workplace when handling lubricants. The 5S method can give us a better overall view of what happens in our lubricant storage areas.

Let’s “Sort’ This Out

When walking into many facilities, there are usually a lot of oil drums, buckets, or items used for lubrication scattered all over the facility. However, some facilities are fully equipped, nicely stocked, and have dedicated lube rooms. The first step in our process is determining what is needed and what is not.

In this case, the best place to start is with an inventory list developed by physically identifying the items on the plant. If this is the first time this exercise is being conducted, then it is critical to perform this check in person rather than rely on the information entered into the CMMS (if one exists). Sometimes, not all the information may have been captured in the CMMS when it was entered initially.

A good idea would be to divide the plant into various sections and perform your audit one section at a time. It would be ideal to note the following during your audit:

• Name of the lubricant (for example, Turbo S4GX)
• OEM (for example, Shell)
• Viscosity grade (ISO 46)
• Expiry date (use this opportunity to find out if you have expired lubricants in stock)
• Quantity (use this opportunity to find out if the inventory levels are accurately reflected in your CMMS).

Armed with this information, we can correlate this to the equipment needing the associated lubricant. In this instance, we can compile an asset listing and assign which lubricants are used for the respective assets. With the asset listing, we should also identify the oil requirements for the specified component. This way, we can develop a table similar to Table 2 below.

With the information collected in Table 2, we can easily sort through the lubricants we have in use and match them back to the requirements of the assets. This is where we can identify if we have duplicated products or products that serve the same function but are represented by different brands. This is the beginning of the consolidation process.

If you enter this information electronically, it will be easy to sort. You can group similar applications together and then compare the application’s requirements to the current lubricant. This will help you determine if you are using a highly specialized lubricant for an ordinary application or if the incorrect lubricant was used from inception!

This exercise will be fundamental in gauging your lubrication requirements and then allow you to consolidate some of the lubricants in use. For instance, if there are five different applications of gear oil and many types of oil, we would need to determine if all the listed lubricants are entirely necessary. See Table 3 below and determine if we need these five types of gear oil.

We can begin with the types of oils listed; some have varying viscosities, while others are food grade, and the rest are not. We can include this in a summary table, as seen in Table 4:

Table 4 shows that GB 1005, GB-4005 & GB-4008 all require the same type of oil, a food-grade ISO 220 mineral gear oil. Then why do we have three different types of oils that match the exact description? We can consolidate this oil into just one food-grade ISO 220 mineral gear oil brand. Ideally, the choice will be based on the supplier relationship, the availability of the product, and other cost factors, including delivery to the site.

We can also see that GB-2009 and GB-3003 require a non-food grade ISO 460 oil; however, one is synthetic, and the other is mineral. In this case, we can review our asset specifications and determine if a synthetic was required or if a mineral oil is preferred for these applications.

In this case, we could be using a higher-specification product and paying a lot more when the asset does not require it. This decision could have occurred in the past when synthetic oil was the only available grade of oil for that component, and it was ordered from the supplier to keep the plant running. However, if we consolidate these two, then we could go with a regular mineral non-food grade ISO 460 oil for both applications. 

By understanding our applications and where we’re using these oils, we’ve just cut down our list of 5 gear lubricants to 2 gear lubricants! These will be much easier to manage in our inventory than keeping track and ordering from 5 different suppliers.

Additionally, your staff will have less to worry about as they know which specific oil is for the ISO 220 grades and which one is for the ISO 460 grades, making it less complicated and reducing some human errors.   

The Other S Factors

The remaining 4 S factors can also be included in our journey to improve the overall quality of our approach to machinery lubrication. Once we have “Sorted” our lubricants by making sure we have what is necessary, we can move on to “Set these in order.”

In this step, we can ensure that all the types of lubricants are stored in a clean, dry, cool place away from water, direct sunlight, or drastic temperature changes. We can also observe the “FIFO” rules, where the first lubricant that enters the warehouse is also the first to leave and be used in the equipment. Additionally, we can have lists stating the assets in which the assigned oils are to be used and place matching tags on the equipment and dispensing containers to reduce mix-ups of the wrong lubricant being used.

The third “S” talks about “Shine,” which relates to keeping the work area clean. We can also apply this to our oils with the dispensing equipment, making sure we use clean, dedicated dispensing bottles, not the fancy, galvanized, open-top containers where someone showed off their welding skills. Those galvanized containers are huge sources of contamination, which will degrade our lubricants at a faster rate.  

With the fourth “S”, the process of “Standardizing” is used. This was incorporated in the first “S” during our sorting session, where we grouped similar lubricants and standardized them for various applications.

The last “S” is to “Sustain” or make the 5S process a habit. This would involve performing audits every year to ascertain if any new lubricants entered the facility and if they, in turn, should be consolidated with others that perform the same function.  

Benefits of Oil Consolidation  

There are many benefits to the consolidation of lubricants, but here are a few that stand out:

Reduced Cost of Inventory

For warehouses that stock many types of lubricants, there is a cost attached to holding these high stock levels, especially when the lubricants will not be consumed as quickly. However, with a consolidated stock, these levels can deplete at a faster rate than the specialty one or two lubricants, which may be used occasionally by certain assets. This helps to reduce the overall holding cost of the stock.

Reduced Human Error

With lubricants from many different suppliers, it is very easy for someone to get confused and use the wrong lubricant in the wrong application. This can lead to unplanned downtime and a possible flush of the entire system, depending on the level of cross-contamination. However, with a consolidated stock, the risks associated with humans utilizing the wrong lubricant become minimized. 

Reduced HSE Risks

When removing a drum of oil from storage, a forklift may be required (depending on the location). If there were different products from various suppliers, it may be difficult to access the ones needed or may require extra work to remove the additional drums from the other suppliers before the operators gain access to the lubricant they need. With a consolidated stock, it would be easier to access the lubricant needed, and there would be less risk associated with removing it from stock.

There are various types of handling procedures associated with the different lubricants. As such, more procedures will be involved for disposing and handling various oils. This can also increase the HSE risk if someone is not fully aware of how to handle specific lubricants. With a consolidated stock, the HSE personnel will not have as many procedures to be aware of when handling these lubricants.

Reduced Operational Costs

Personnel would no longer be required to handle all the invoicing and payments of several lubricant suppliers for the various brands. This will reduce the hours the accounting department spends on the necessary paperwork and bank transactions for several vendors. Additionally, warehouse personnel will not be tasked with receiving products several times a day from the various suppliers and producing the accompanying paperwork. This can reduce the overall operational costs.

There are many benefits to the consolidation of lubricants, especially in our facilities, but it begins with understanding if we are using them in the correct application or if we’re using an over-specified lubricant in a lower-tiered application. Auditing your facility will assist in making this process easier, as noted above. We all have our role to play in consolidating lubricants to ensure that we have a safer, more efficient plant.   

References

ASQ. (2024, OCtober 19). What are the Five S’s (5S) of Lean. Retrieved from American Society for Quality: https://asq.org/quality-resources/lean/five-s-tutorial

To truly measure the success of your lubrication program, you need to look beyond consumption and focus on key lubrication metrics.

Is Lubricant Consumption All I Need to Measure Success?

Of course, but like most statistics, there are lies, damned lies and statistics. Figures can be fudged. Take the example of a maintenance manager telling me he had ordered additional lubricants on this year’s budget so that next year would show a decrease.

Or how about simply reducing the frequencies of greasing and extending oil drain intervals? The program has succeeded by that measure, but has reliability been achieved?

Naturally, any lubrication-focused reliability program should see a reduction in lubricant consumption, but do not be disheartened to find this is not the case, particularly in the first few years of the strategy, as more flushing activity is undertaken to deal with past mismanagement.

If employing condition-based lubrication using ultra-sound, the increased greasing activity may also see a rise in throughput.

Consumption should be reduced in the longer term, especially by addressing leakage and waste issues. However, this metric or Key Performance Indicator (KPI) needs to be managed correctly, and the trend will only show a true reflection in the longer term as the program settles in.

Aren’t There Other Ways to Measure the Success of a Program?

Certainly. The target of the program is to improve reliability. Lubrication success is just part of the overall success, but monitoring issues like:

• Improvements in the Mean Time Between Rebuilds (MTBR) of assets such as the gearboxes, pumps and electric motors
• Improvements in the Mean Time Between Failure (MTBF) of lubricated components such as bearings

As stated, lubrication, while a significant root cause, is only part of the overall reliability strategy. Therefore, it could be argued, particularly with rotating equipment, that some benefits may come from alignment, balance, and fastener tightness improvements. That said, these are all still valuable KPIs in an overall reliability strategy rather than for measuring the success of lubrication.

What Do Bathroom Scales and Oil Analysis Have in Common?

Bathroom scales are simply a reflection of a lifestyle. A reflection of the effort one puts into a proactive lifestyle is dietary and exercise regimes.

In that sense, an oil analysis program reflects a company’s lubrication lifestyle.

Implementing an oil analysis or condition monitoring program will not magically increase reliability. Reliability will stem from changes made in maintenance practices, and any condition monitoring program is simply an effective tool for measuring progress in controlling the root causes of poor reliability.

Can Oil Analysis Be Used to Measure the Success of a Lubrication Improvement Plan?

Yes, simply by monitoring the overall results and seeing if the overall trends are heading in the right direction. Let’s look a little closer at how this can work:

The Oil Health Trend

How many times are the reports recommending oil be changed?

How often do the oil health values exceed the caution and critical alarms?

If lubrication best practices are in place and successful, oil life will benefit. Oil will last longer, and consequently, fewer alarms will be triggered.

Set a goal for the various lubricant types regarding anticipated life and the desired targeted life extension. Trend how often the limits are exceeded for the oil health reports, aiming for a yearly reduction.

The Contaminants Trend

How often do the measured contamination levels exceed the caution and critical alarms?

If contamination control has been implemented in all its forms (storage, handling and transfer, and machine protection) as part of the lubrication improvement plan, then this should start to show in the oil analysis data, with reducing levels overall. The cleaner the oil, the greater the chance of success.

Set Target Cleanliness Levels (TCL) for each asset based on the desired life extension and other factors, such as criticality, and ensure these are met. Trend the number of times the oil analysis reports show caution (typically three consecutive readings over the TCL) or critical (one reading over the TCL) alarms.

The Wear Debris Trends

How often do the measured wear levels exceed the caution and critical alarms?

Wear results from various root causes, including lubrication, oil health, and, more likely, contamination levels. Therefore, one can expect to see wear debris levels reduce as the program rollout continues. However, remember that other root causes exist beyond lubrication, so some of the gains in this area are potentially, as said earlier, from alignment, balance, and fastener tightness improvements.

So, Oil Analysis Reflects the Lubrication Lifestyle, But Are There Any Other Metrics Or KPIs We Need To Consider?

Definitely. Just as an athlete has a program that must be maintained, so must the lubrication activity. Lubrication activities are implemented for a reason: to create reliable operation.

Therefore, the biggest KPI or metric in this case would be achieving 100% completion on the lubrication tasks. If this action is undertaken, success will be assured.

Add in KPIs for monitoring the rollout, such as completion of aspects of the implementation like:

• Tagging the machines with the relevant information
• Upgrading the machines for contamination control

We should remember that education is also crucial to implementation and success. Without the awareness and knowledge to support the program, business as usual will result, with staff reverting to old ways.

Therefore, another key metric is the rollout of training. Set a KPI for getting personnel trained to the appropriate levels that their roles require, be that awareness training or achieving the required levels of certification by an independent body.

But Is There a Way To Compare Our Performance Against An Industry Average?

Be very careful about comparing yourself to average! The average is just that. You can pat yourselves on your collective bacs because you may be better than average. Is that enough in today’s world of global economic challenges?

What About a Global Standard For Lubrication?

Just as the ISO 55000 series of standards were introduced for asset management, there is a standard for lubrication. Introduced by the International Council for Machinery Lubrication, the ICML 55™ is a series of standards for lubricated assets.

There are three sub-standards under the ICML 55™ that assist in the process of making ISO 55000 “Asset Management” concepts directly applicable to lubrication programs.

ICML 55™ is an enabling standard in strategic and operational alignment with the broader ISO 55000:

• ICML 55.0 “Overview”
• ICML 55.1 “Requirements”
• ICML 55.2 “Guideline”

Jointly authored by an international team of forty-five subject matter experts, this standard offers a detailed, practical consensus on lubrication management systems and processes for effectively managing lubricated physical assets.

The adoption of ICML 55.1 requirements, as augmented by ICML 55.2 guidelines, will enable an organization to achieve its objectives of effectively and efficiently managing its physical lubrication and lubricant asset policies, strategies, and plans.

ICML 55.1 identifies and defines requirements rather than explaining how to do it, which allows for customizing to suit specific needs rather than trying to force-fit a process.

It should be noted that while intended to align with ISO 55001, the ICML 55.1 standard is the work product and exclusive intellectual property of ICML. It is neither explicitly nor implicitly endorsed by the International Organization for Standardization (ISO) or any other standards body.

How Does Implementing ICML 55™ Help My Organization In Terms Of Measuring Our Lubrication Program Success?

If there is any doubt as to whether any stones are left unturned regarding lubrication, the ICML 55™ covers all aspects. If implemented correctly, then success will follow. It is successful not just in terms of reliability but also in terms of health, safety, and sustainability through environmentally aware lubrication.

More to the point, with the forthcoming ICML 55.3 – “Assessors’ Conformance Guideline,” annual lubrication program reviews and audits will ensure the business remains on track to achieve the end goal.

What Else Should We Consider?

Never be afraid to publish your success! Consider writing monthly for the company newsletter. Initially, lay out the new program’s strategy and goals, and then follow up with the trends from the KPIs and any short-term success stories.

Also, consider putting up new charts each month showing the performance.