To optimise load capacity of your linear ball bushing bearing, you need to orientate it in relation to the applied load. For maximum capacity the linear bearing must be oriented so that the load is distributed between load bearing tracks.

Using a polar graph to map the orientation of your bearing as a factor of maximum capacity, it’s easy to see the relationship between load vs orientation. This is called a load correction graph, and they are included on all Thomson linear ball bushing bearing data sheets to help you.

Here’s what the graphs tell us:

  • Where the load is applied over multiple tracks, the capacity is at its highest
  • Where the load is applied directly over the bearing track, it is at its lowest

What do we need to do?
When the load is only over one set of bearing tracks, we must derate the load capacity by clocking the bearing at a different angle inside its housing to distribute the load over multiple bearing paths – this is known as the correction factor of its maximum load.

What about open linear bearings?
In most cases it’s not practical to position open type linear bearings to maximise load capacity because the shaft supports restrict rotation.

That said, to optimise installation and performance, you should still have a clear understanding of how applying a load in different directions affects the load rating and design of your bearings.

Using polar graphs to map the load correction factor vs load orientation, we can see the forces that push the bearing down onto the rail are the same as with a closed bearing. But the capacity for loads pulling opposite the slot  (trying to pull the bearing off the rail) is greatly reduced. Some bearings can even resist a pull off load of around 25% of its maximum load.

If in doubt ask for support
Optimising load capacity is an important factor in getting the most out of your bearings, so be sure to ask your supplier for technical advice.

Bowman stocks a wide range of Thomson linear ball bushing bearings. DM me your questions on optimising load capacity, stock availability or delivery times.


Bearings are not (and never have been) a one size fits all solution – let’s take load vs speed for example. 

To put it simply, load and speed – or revolutions per minute (RPM) – are relative and will, no matter how we spin it – equal heat. If you specify the right bearing and maintain it appropriately, the heat will be minimal and won’t cause a problem. But if you specify the wrong bearing, there will be too much heat and you’ll be plagued with unplanned downtime.

Here are my top tips for specifying bearings according to load vs RPM:

High load, low RPM
Applications like cable rollers, crane wheels and pulley systems are characterised by very high loads, and comparatively low speeds.

The key considerations for bearing specification should therefore be:

  • Choosing materials capable of handling substantial loads
  • Ensuring proper lubrication for slow speeds to prevent wear
  • Selecting bearing designs that distribute the load effectively

It’s important to pay special attention to factors such as alignment, clearances, and the potential for static loading. Regular maintenance is also crucial to extend the bearing’s lifespan under high-load, low-RPM conditions.

Low load, high RPM
When specifying for high-speed applications where load isn’t a particular concern, like screw, scroll or centrifugal compressors, it’s important to consider these factors in relation to the intended bearing application:

  • Rotational speed
  • Radial and axial loads
  • Material properties
  • Lubrication requirements

Remember to evaluate manufacturing precision for high-speed stability and assess potential heat generation to ensure the bearing meets specific tolerances and clearance criteria. 

Additionally, factor in potential dynamic forces and vibrations associated with the application, and consider any environmental conditions that might impact performance.

Collaboration and consultation
When it comes to specifying bearings – no matter the variables – you are not alone. Collaborating with a manufacturer that offers consultative advice and a wide choice of bearing materials and types will ensure you avoid downtime even in the toughest applications. 



When you need a new bearing installed fast, it can be really tempting to ignore tiny details like no visible joint gap on the inner race halves and clamp rings – don’t. 

Here’s why:

No joint gaps can indicate a problem
The joint gap ensures the inner race halves are clamped tightly to the shaft. If there are no visible joint gaps, this indicates the shaft is undersized, or you have the incorrect size of bearing.

The bore of the Bowman Split Bearing inner race is manufactured to the same size and tolerance as the shaft and it is made with joint gaps which are cut at an angle allowing each roller to pass over the joint gaps progressively without impeding on the performance of the bearing. The gaps prove the two halves are not touching each other – hence when the clamp rings are fully tightened the race will be firmly fixed to the shaft.

If you do not have gaps at both joints, it means something is wrong. Stop the installation and get in touch with your supplier for support. 

Installing a bearing with no joint gaps will result in damage and potential failure 
If there were no gaps at the joints during installation, or the gaps were incorrectly set, the race halves will press against each other as the rollers pass over the joint during operation. The result will be fractured joint faces resulting in particles of the inner race flaking off and entering the bearing, causing further damage and potential bearing failure.

It is easy to spot a bearing that has been running with incorrectly set joint gaps because there will be damage at both faces of the ‘touching’ joint.

Getting it right
To help you get it right, prolong the life of your bearing, optimise operation, and avoid additional downtime, here’s our best practice advise:

  • Pay close attention during the initial fitting of the inner race halves, use feeler gauges to check and equalise the gaps before finally tightening and applying the torque to the clamp ring joint screws
  • Soft, compressible packing can be used to maintain a gap, but ensure it doesn’t protrude beyond the joint face – if it enters the roller path it will cause issues with the roller rotation, and if it enters the bore of the race it will cause issues with the inner race not seating correctly on the shaft
  • The gaps should be approximately 0.5mm each side depending on the accuracy of the splitting operation
  • Try to make the joint gaps equal but when this isn’t possible ensure there’s a gap at each joint, even if it’s a 60/40 or 70/30 gap ratio
  • The clamp rings are manufactured with a similar joint gap, this is to ensure the full tension force of the screw is used to clamp the inner race to the shaft. Use the same best practice as you did with the inner races but note the larger joint gap of approximately 1.0mm at each joint 

No gap, no operation
The bottom line is simple, if there are no joint gaps, then the bearing should not be given the green light for operation. The bearing life will be reduced, meaning another investment and additional downtime sooner than necessary. 

If you’ve suffered a breakdown and need support quickly, DM us. We hold substantial stock inventory and can could reduce your wait considerably. 


It has been billed as a disruptive 3D printing technology for a new era of manufacturing and HP’s patented Multi Jet Fusion (MJF) technology is already delivering on its promise for faster, more material-efficient and more detailed parts without compromise, compared to traditional component manufacturing techniques. 

But how does it work? And what are the true benefits? Here is a quick dive into MJF and the possibilities it opens up.

How is Multi Jet Fusion different from other 3D printing techniques? 

In practice, MJF produces parts in a similar way to the long-established Selective Laser Sintering (SLS) technology, adding sequential layers of polymer powder into a build chamber.

Like SLS technologies, the feedstock comes in the form of powder which is spread in a thin layer (of 80 microns) across the build platform before being melted in predetermined areas. Another layer of powder is added and selectively fused to the layer below, building up the part layer by layer.

The big difference is that MJF is a more advanced technique, allowing greater speed and precision in the printing process. Instead of using a laser to fuse parts, HP’s patented process jets a fusing agent onto the powder surface and uses a high-powered heat lamp to selectively fuse areas of each layer together.

What are the benefits? 

The main advantage over SLS technology is speed. HP’s Multi Jet Fusion technology enables production of high-quality parts up to ten times faster than other 3D printing solutions in the marketplace today, without the expected increase in cost. 

Like SLS, it can produce parts in quantity within a three-dimensional build space, without needing to incorporate support structures, but parts produced with MJF have more uniform mechanical properties and greater part detail thanks to the application of a detailing agent around the edge of parts.

In addition, because it is built on decades of experience and continued investment from HP in inkjet printing, material science and imaging, MJF benefits from continued technological advancement and an ever-broadening material portfolio. 

What are the possibilities?

Bowman 3D uses MFJ technology to print in mostly PA11, although PA12, PA12 GB (glass filled) and TPU are also supplied. Standard finishes include natural, dyed, vibro polished, or a combination of both, while bespoke painted finishes and coatings are also available.

The general tolerance for parts in PA11 is +/- 0.3mm or 0.3% (whichever is greater), but the reality is that for most smaller parts, significantly better tolerances can be achieved.

Part sizes are limited by the dimensions of the build volume: 380mm x 284mm x 380mm. However, it is possible to exceed one of these dimensions by orientating the part appropriately in the build. We can also help to split large parts into smaller assemblies. 

Want to know more? Simply comment “More info” below and we’ll send you a technical white paper on HP Multi Jet Fusion.


Linear ball bushing bearings for high-load, high-speed applications allow for ultra-smooth travel along the shaft with precision, but only when the correct clearance is applied between the shaft and bearing. 

If your bearings are not travelling smoothly, you may need to adjust the clearance to reduce preload. Likewise, if they are not precise in their movement, it is likely that the lash needs adjusting.

Here are four things you need to know when adjusting pillow blocks to remove the lash, avoid drag and optimise precision of your linear bearings.   

  1. Simple steps to adjust the clearance

Pillow blocks have an adjustable inside diameter which allows engineers to reduce the lash, or play, which is of course the clearance between the shaft and the bearing.

Adjustments to the inside diameter could not be easier. Simply find the adjustment screw and use a hex/allen key to loosen it. Make sure the pillow block is mounted to the shaft (you can check this because it will rotate easily on the shaft) and tighten the adjusting screw gradually until the linear bearing just starts to grip the shaft.

  • Avoid over-tightening

Stop tightening the adjustment screw as soon as you feel a slight increase in force when rotating. This indicates zero play (near frictionless movement) or slight preload (the force acting on the rolling elements) to minimise ball skidding and reduce axial play.

Ideally, you want to be able to move the linear bearing along the shaft without roughness and rotate it without drag, using only light pressure. 

  • The dangers of high preload

If you find you can’t move the bearing using only light pressure, then the preload is too high. It is important to avoid excessive preload because this will cause rough operation, can shorten the lifecycle of the linear bearing and may lead to damage of the bearing or shaft. 

  • Twin pillow blocks

Finally, if using a twin pillow block, one linear bearing should be adjusted while the other one is loose. Note the  positioning of the adjustment screws (e.g. 10 o’clock or 2 o’clock) or torque wrench reading of the adjustment screw for the first bearing, then loosen it and adjust the second linear bearing. Once the clearance in the second bearing is correct, then return the first bearing to its correct setting.  

For more support with linear ball bushing bearings, DM me or call +44 (0)1235 462 500.


Tracked utility vehicles are the backbone of agriculture, and without them farmers can experience costly delays. Operational reliability is essential for this sector, so these machines must be designed to transport high loads while withstanding mud, water, uneven ground, changing temperatures and unplanned impact. 

To keep the tracks turning, accurate bearing specification is critical. Here’s everything you need to consider when specifying bearings for rubber tracked farm vehicles:

Load capacity

Different tracked vehicles will perform different tasks, which means load capacity is not a one size fits all measurement. It’s essential that you identify the expected loads (radial and axial) and specify a bearing that offers sufficient load carrying capacity for the machines intended purpose. 

Not doing so will significantly increase the likelihood of premature bearing failure. 

Rotational speed

Just like load capacity, speed is another variable that will change depending on the tracked vehicle you are specifying for. You must consider the rotational speed requirements of each particular vehicle and choose a bearing that operates well within those speed limitations.

Bearings that cannot cope with the speed of an application will fail quickly once in operation. 

Environmental factors

Agricultural operating environments can be challenging, and will have a direct impact on the performance of the bearings you choose. Temperature, humidity, and exposure to contaminants can all affect bearing performance if you don’t specify a product that has been specifically designed for such environments. 

Material selection  

Incorrect material specification is one of the biggest causes of bearing failure and for arduous environments it’s even more important to get it right. The right material will resist wear and corrosion, extending bearing life and reducing downtime – essential for time critical applications.

Bearing type

To avoid excessive friction and wear, it’s important to use the right type of bearing for your rubber tracked vehicle. This could be a ball bearing, a roller bearing or a plain bearing, and often seeking professional consultative advice on this can help you get it right.

Agriculture is one sector that really benefits from low-maintenance bearing options like Bowman’s BowMet bearings, because vehicles are often used daily, with little to no time for maintenance. 

Cost vs performance

CAPEX (purchase) cost vs lifetime cost can be a difficult balance to get right. Under-specifying your bearing to save money up front, or over-specifying in an attempt to avoid downtime are both likely to lead to unnecessary expense and performance issues. Carefully considering the other factors in this list and specifying a bearing that meets the criteria is the best way to improve bearing life and avoid unplanned downtime.

Vendor selection

Choosing a reputable bearing supplier is essential. Look for someone that can provide a “whole of market” portfolio so you are guaranteed impartial application-specific product recommendations. 

Don’t fall for low-cost, low-quality options which will likely lead to frequent failures and increased costs in the longer term.

Need help?

If you need help specifying the right bearing for rubber tracked vehicles, DM me today for a no-obligation audit of your requirements. 


It’s no secret that proper bearing maintenance prevents downtime and saves money, and in fact research shows that running a piece of equipment to the point of failure could cost up to 10 times more than investing in a program of regular maintenance1.

In reality, despite the damming evidence that maintenance pays dividends, we all know that time, resources and labour costs are all factors that determine how thorough a maintenance schedule can be from one year to the next. 


So, assuming your bearings have been correctly specified for your application (another massive cause of failure!), here’s a simple list of three money-saving tips to get you started with proper linear bearing maintenance:


Bearing maintenance needs to be regular, and that includes lubrication. Proper lubrication is required for rolling element bearings to last, even under light loads.

To achieve the dynamic load capacities listed in the catalogue, your bearings will require the right level of lubrication, applied at the right intervals. 

A typical minimum lubrication cycle is once a year or every 100 km of travel, whichever comes first. More frequent lubrication may be required based on application specifics, like the duty cycle, usage, and environment. 

Excessive clearances, contaminants, heat and vibrations are all factors that create the need for more frequent lubrication. Another option is lubrication-for-life accessories that provide continuous lubrication for the life of the bearing. 


Planned downtime usually costs less than unplanned downtime, and replacing a fully operational bearing costs less than a breakdown, so replacing linear bearings on schedule before failure makes good business sense. The L-10 life of the bearing can serve as a rough guideline as to when bearing replacement is required. Keep in mind though that, based on its definition, L-10 life means that 90% of bearings will last longer than their L-10 life while 10% will fail before their L-10 life is up. Of course, under difficult environmental conditions or higher than design loads, bearing life will be considerably reduced, so replacement schedules should be adjusted accordingly.


You can guarantee that when a bearing fails it will be at the worst moment – like when there’s no spare parts in stock or there isn’t a qualified team member present to perform the change-out.

This extends downtime which means more money down the drain.

To avoid this, invest in training your operatives to proactively spot signs of pending failure. The right training makes it possible to predict oncoming bearing failure so it can be replaced at a much lower cost at a time of your choosing. Make sure you have plenty of bearings in stock too so they are available when you need to quickly deal with an urgent problem or preventative maintenance task.

Preventative maintenance requires regular bearing checks to identify potential signs of failure. Here’s a quick check list:

  • Dry-running: Run your finger along the shaft and rail, you should be able to feel a thin film of lubricant
  • Contaminants: Check the bearing for corrosion or contaminants
  • Environmental changes: Examine the environment to see if it has become more challenging
  • Metal fragments: Check the bearings, bearing outer race and shaft or rail for metal fragments 
  • Clearance: An increase in clearance is sometimes a sign that a bearing is about to fail
  • Noise and vibration: Unusual noise or vibration is often an indicator of a bearing problem

Remember to always ask your supplier for support if you discover something unusual during your bearing inspection. 

If you want help maintaining your Thomson Linear Bearings, if you’d like to order more stock so you are prepared for an emergency, or if you want to order replacement bearings for your maintenance schedule, I am here to help.


Casting, moulding, and machining are all traditional manufacturing methods used for component production – but 3D printing is becoming mainstream too. 

Short, reliable lead times and digital warehousing aside, 3D printing offers a range of other value add solutions that can improve product performance and save money compared to conventional manufacturing techniques. 

Here’s five of them:

Weight saving

Producing parts that are lighter, without compromising performance, requires the use of lattice or mesh structures that can be prohibitively expensive using traditional subtractive or formative production methods. 

This cost barrier is easily overcome with 3D printing. Known for making light work of complex geometries, 3D printing can deliver the weight reduction you need, while maintaining the strength and robustness required for optimal component performance.

Reduced assembly

Many components are manufactured in pieces and assembled afterwards because of inherent restriction in traditional production methods. Using 3D printing to produce production volume parts affords design freedoms that could allow you to consolidate complex assembles of different parts into a single printable design. 

This not only saves on labour and resources (sometimes making an entire assembly line obsolete), but also improves the appearance and functionality of the final product.

Easy ergonomics for ease of use

When creating a device for manual operation, curved, organic shapes are often preferable. Ergonomic shapes are often difficult and expensive to produce, especially with subtractive manufacturing methods. 

Improving user experience with curved ergonomic designs is far easier with 3D printing, and can be achieved without additional costs or production time.

Incorporating logos and serial numbers

Embedding logos or serial numbers into the design of a component offers a quality finish and can remove a step from post-production assembly.

There are practical advantages too. When permanent logos or markings are required throughout the component’s operational life, embedding them into the component material will prevent the loss of stickers over time. 

Mass customisation 

The rise in orthotic teeth aligners is a perfect example of mass customisation using 3D printing, and the concept of offering personalised elements to mass produced parts is becoming increasingly popular in other sectors too. 

With 3D printing, your stock is held in a virtual warehouse, where your designs can be iterated and printed on demand, with fast lead times and no minimum order quantity. This enables manufacturers to offer customisable options at the point of purchase for high-value items.

Margins of gain with small tweaks

By making small tweaks to your component design process, it is possible to see small margins of gain in profit and product performance. 

There are plenty of other ways 3D printing can add value, why not share your next design with us to learn more? Send it to 3dsales@bowman.co.uk.


Did you know that only 10% of industrial equipment can physically ‘wear out’ which means over 90% of mechanical failures are avoidable?1

The best way to avoid failures is of course predictive maintenance rather than reactive maintenance. In other words, spotting and trouble-shooting issues before they become a significant problem. Condition monitoring sensors are the most effective way to do this and can identify problems before they would be apparent to the human senses. 

Condition monitoring is a worthwhile investment, but it isn’t something all businesses can afford right now. In the absence of data-driven maintenance, it’s important to conduct regular, effective  bearing health checks to help prevent unplanned downtime. 

Here’s a simple four-step process for bearing health checks if you don’t yet have condition monitoring:

Step one: Conduct a visual inspection

If your process allows for a brief planned break, carry out a visual check on the bearing. In the main, you are looking for visual wear characteristics on the raceways and rolling elements including fretting (discolouration) and spalling (peeling metal). Both of these could be signs of either poor lubrication, misalignment, poor fitting practice or fatigue. Whilst the shaft is running, check to see if there is visible movement of the housing. This would indicate looseness within the bearing brought on by the issues mentioned above. 

Don’t forget to inspect the seal faces for an unconventional or excessive wear pattern, as well as the shaft face itself – is the shaft the same diameter where it contacts with the seal?

Take photos of your findings so you can compare them each time you inspect your bearing. This will help you identify any less obvious changes. 

Step two: Listen for noises and monitor vibration

By listening to the bearing in operation, it’s possible to identify the presence of deterioration or damage. If the bearing is in optimal condition, it will produce a soft humming sound, but irregular or unusual sounds like squeaks or grinding could indicate a condition issue. 

Listening to changes in vibration is also important, but it’s worth noting, that manual sound monitoring isn’t always effective for vibration management and digital vibration monitoring via sensors is a worthy investment. The onset of mechanical issues is almost always accompanied by an increase in vibration levels and the characteristics of the vibrations can indicate the type of fault at play. 

Step three: Pay special attention to the grease

Incorrect lubrication, or the absence of grease altogether is one of the most common causes of bearing failure. When inspecting your bearings, pay special attention to whether the bearing is running dry, or whether the grease has discoloured or separated from excessive heat or vibration– this could be a sign of too much or too little grease. Likewise, the presence of too much grease can also cause serious trouble, especially in high speed applications – always use the manufacturer-recommended quantity and refer back to this during your inspections.

You may notice the grease looks like marmite, and you may smell carbon which means it has been burning.

Also check for lubricant leaks in the areas surrounding the bearing and ensure the labyrinth seals are filled with grease for maximum protection. 

Just like in step one, take photos of your findings so you can draw accurate comparisons each time you inspect the bearing grease. 

Step four: Monitor temperature during operation

Assuming the operating conditions haven’t changed, the temperature at bearing locations should remain consistent. An increase in temperature could be a sign of bearing damage and potentially imminent failure. Hand-held infrared thermometers are readily available, economical and can prove useful in spot-checking bearing temperatures. 

That said, always remember that a rise in temperature is natural immediately after your initial machine power-up and after each fresh application of grease, and these increased temperatures can last a couple of hours.

Bonus step: Ask for support and guidance

Industry is evolving at a rapid rate as we try to increase output, quickly and cost effectively. In doing so, we’re putting our machinery under considerable pressure. 

These new-found performance parameters are bound to impact the wear components of our equipment and bearing inspections may not always go to plan. 

If you see, smell, hear or detect anything unusual, ask for help and guidance from your supplier so they can support you in avoiding unplanned downtime. 


Bearing failures can be expensive, disruptive and in some cases dangerous, but did you know that the three most common causes of bearing failure can be avoided before the bearing is even operational?

Here are the three top causes of bearing failure, and how to avoid them:

Bearing type – the bearing you have chosen doesn’t suit the application

The number one cause of bearing failure is using the wrong bearing to begin with – something that is easy to do without the right specialist insight.

There are plain bearings, ball bearings, roller bearings and needle bearings to name just a few, and each of these product groups have many variations within them; for example, plain bearings can be sintered, wrapped, plastic, composite or machined from various solid materials. Ball, roller and needle bearings can be offered in numerous configurations.

Often, when customers come to me they understand what their bearings need to do and the parameters in which the bearing must operate – the load, speed and environmental requirements  – but they don’t always know what type of bearing can deliver those capabilities most effectively, and importantly, cost efficiently. 

This will influence not just the cost of the initial purchase, but potentially other factors including the cost of ongoing maintenance, lifespan of the bearing and even how efficiently the equipment works. 

Material selection – the material you’re specifying isn’t best matched to your application

Plain bearings have long been manufactured in a broad range of materials – sintered bronze, sintered iron, rolled bronze, cast bronze, various plastics, various composites, stainless steel and other  materials such as BowMet®, which is made from the ToughMet® alloy. 

Ball, roller, and needle bearings can also be offered in high carbon chrome steel, stainless steel,  ceramic and many other materials. 

Add to this the constant innovation in material science and it’s easy to see why we often see customers who are using the correct type of bearing, but not the correct material.

Lubrication – you can’t (or aren’t?) maintaining your bearings correctly

Bearing lubrication is an ongoing commitment to optimise machine performance and component lifespan, but many end users struggle to commit to a regular, adequate, lubrication schedule.

In some sectors, like marine for example, it is either difficult, cost-prohibitive, or impossible to service bearings because of the environment in which they are operated. In others such as agriculture or construction, time-poor farmers or plant operatives simply will not take the time to keep bearings adequately lubricated. 

If either of these scenarios describe you, or your application, then understanding what maintenance-free or low-maintenance options are available to you can prevent inevitable bearing failure.

One simple solution

Avoiding these three common pitfalls is easy. By working with a whole-market manufacturer or supplier that offers a wide range of bearing types and a consultative approach, you will have access to experts that can guide you on best practice bearing specification.

If your supplier’s product portfolio is unrestricted, you can rest assured you’re getting the right bearing for the job, and not  just the type that they manufacture or stock

Whether it’s a change in bearing type, bearing material or a switch to a lubrication-free solution, a consultative approach to bearing specification is a sure-fire way to prevent downtime. 

If you haven’t considered alternative bearing solutions for some time, why not check you are using the right option for your application? There may be newer solutions that could minimise downtime and save you money. For support DM me or call +44 (0)1235 462 500.