Bearingsize calculator

In our previous article, we discussed the two common types of ball-bearing preload, factory preload, and spring preload. Sometimes those types of preload need to be further optimized or adjusted, other times the factory preload is good as-is and doesn’t need any adjusting.

We know that not every application requires super, high-precision bearings. We stock other industrial parts from quality brands.

Bearing dimension chartin inches

For example, aluminum is considered a soft material, so if we compare it to 52100 bearing steel, the thermal expansion for aluminum is about double that of steel. This means the aluminum expands twice as much as 52100 bearing steel.

Our onsite engineers geek out enjoy working with other engineers to help them put together a strong preload strategy. And they’d enjoy working with you too! Reach out to us on our contact form or give us a call at 800.323.5725 with any questions you may have.

These self-aligning, or "Floating" bearings allow up to 2.5 degrees of misalignment. They are used for the top roller on some KT and Bona belt sanders.

Bearingsize Calculator in mm

Bearingnumber and sizechartpdf

Preloading a ball bearing is required for angular contact bearings because they need constant contact between the balls and raceway, which is achieved through bearing preload.

These bearings have 2 rows of balls to handle higher loads. Note that 32 series and 52 series bearings are interchangeable.

Includes built-in ball bearing support. Supports MEDIUM loads & low to medium torque capacity: 53 to 267 Nm. Bore (ID) sizes: 17 to 40 mm (0.669 to 1.57 in)

The constant contact between the balls and raceway allows angular contact bearings to operate at higher speeds and have higher load ratings than a common radial ball bearing.

Inch dimensions are rounded to the nearest thousandth. ID is inside diameter, OD is outside diameter. Not all sizes listed are available or in stock. Some bearings are listed for reference only.

No built-in ball bearing support. Has no RPM limits & Supports high torque needs: 609 to 14,060 Nm. Bore (ID) sizes: 38.09 to 220 mm (1.499 to 8.66 in)

The faster the rotational speeds (RPMs) the more centrifugal force is generated. Centrifugal force produces a powerful outward force on the balls as it rotates around the bearing.

Regardless if you want to change the preload or you’re happy where it’s at, you need to be aware of these three outside influences that could change a ball bearing’s preload:

When creating your preload strategy, make sure to think about the amount of force that will be generated when operating at full speed. Once you know this, then you can balance it out with the right amount of bearing preload.

If there is a known static axial load, like a heavy vertical shaft, then this needs to be considered in a preload strategy (and with the bearing arrangement).

BearingID ODchart

Preload counters centrifugal force and forces the balls back down in the right spot to keep the balls at their designated contact angle.

Without enough preload, a high-speed application with a 15°(C) angular contact bearing could have the contact angle (on the outer ring) decrease to 5° or less, and that contact angle (on the inner ring) increase to 28° or more. This would have dire consequences and could lead to the bearing locking up due to pinching or the balls would go from rolling to skidding on the bearing raceway and cause excessive heat and damage.

No built-in ball bearing support. Good for large orders & low to high torque needs: 1 to 2673 Nm. Bore (ID) sizes: 2 to 240 mm (0.078 to 9.448 in)

If you want to make sure that your shaft and housing units are machined within the right tolerance range, check out our tolerance calculator. Our thermal range calculator will show you how the material of the bearing, housing, and shaft will grow or shrink when in operation.

The best protection for your bearing. Easy to install with a simple “drop-in” next to your bearing. No added space needed. CF seals offer 100% sealing efficiency against splashing liquids.

Metricbearing dimension chart

Understanding these outside influences and how it affects the bearing’s preload will allow you to prepare a strong preload strategy that will counteract those effects.

To summarize, make sure to know the shaft and housing material and the thermal expansion that may result during operation.

Knowing this could save you from experiencing a bearing failure and will prevent press-fit and preload changes from occurring during operation.

Designed with grooves in the outer ring to offer more protection (than our L-type seal) against contamination and direct spray liquids. Liquid gets pushed out through outer grooves when in rotation.

Bearingnumber and sizechartpdf free download

This heavy-duty clutch (aka a hold-back clutch) is good for high torque operations and ensures motion freezes in place. Bore (ID) sizes: 15 to 40 mm. (0.59 to 1.73 in)

Includes built-in ball bearing support. Supports HEAVY loads & has a high torque capacity: 53 to 588 Nm. Bore (ID) sizes: 10 to 60 mm (0.393 to 2.362 in)

Hopefully, this gave you insight into how these three factors: application speeds, application loads, and shaft & housing materials can alter a bearing’s preload.

Understanding how these three factors affect bearing preload will give you the knowledge to counteract it and create a strong bearing preload strategy.

Our GMN Gap Seals are plastic and a great choice for washdown applications, such as food conveyors and food manufacturing facilities

Why is this important? Well, if an aluminum housing is mated with our 52100 bearing steel S6005 angular contact bearing, a 68°F (20°C) rise in application temperature (from room temperature) can create ~11 microns of growth between the steel bearing and aluminum housing. This growth could decrease the press-fit and cancel out the bearing preload.

Bearing dimension chartpdf

The type of mating material could increase or decrease a bearing press-fit, thereby canceling out bearing preload values.

It’s critical to know and understand the type of application load the ball bearings will support during operation. Make sure to also incorporate an effective bearing arrangement plan into the preload strategy.

Why? A heavy vertical shaft that creates a static axial load can increase the load on the lower bearings and reduce (or maybe eliminate) the preload on the upper bearings. In this scenario, both bearings may have an equally short lifespan but for opposite reasons – preload that’s too low vs. too high.