7 Ball Bearings FAQs And Their Answers

Posted by Bradley Irwin on December 22, 2017

Ball bearings have a number of applications and come in various styles or sizes. Here are some of the many questions about ball bearings that are frequently asked, as well as the answers to those very same questions…

1) Can Ball Bearings Ever Be Refurbished?

Generally speaking, the answer is yes, but it honestly depends on the circumstances. For instance, small bearings are often cheaper to replace than refurbish. On the other hand, bearings that have a 6-inch core or higher might yield economic gains or savings through refurbishment. Good candidates for refurbishing typically include slewing rings, spherical roller bearings, and cylindrical roller bearings. Accumulated wear is a factor that has to be weighed in this financial decision, alongside environmental considerations, lubrication, MTBF, and maintenance cycles.

2) MTBF? What Does That Stand For?

MTBF is the mean time between failures, which is a prediction of the elapsed time between two inherent failures of any mechanical system when it undergoes normal system operation.

3) What Exactly Are ABEC Ratings?

The scale is one used to measure ball bearing tolerances and is an accepted standard across the industry.

The scale uses five classes, ranging from the widest tolerances going to the tightest. They are measure 1,3, 5, 7, and 9. A higher ABEC class indicates improved efficiency and precision, along with better capability for speed, although that doesn’t actually mean the bearings spin faster. Note that some critical factors, such as material quality, ball precision, and smoothness of a rolling contact surface, aren’t indicated or specified in an ABEC rating.

4) Do Stainless Steel Bearings Offer Protection From Rust?

The answer to this one is ‘somewhat’ or indeterminate. Stainless steel is not actually rust-proof by itself. However, it is corrosion-resistant, but it still rusts in corrosive environments over periods of time. Having said that, stainless steel corrodes at much slower rates than do chrome alloy steel substances or surfaces. Even then, it’s not so simple.

Many different kinds of stainless steels each have their own corrosion-resistance properties. For instance, 440C stainless steel isn’t nearly as corrosion-resistant as SV30.

5) Just How Fast Can Bearings Actually Rotate?

Some ball bearings have the capability of rotating in excess of half a million RPM. Ball bearings of that magnitude typically see use in defense or experimental applications. Having said this, a bearing’s speed capability often depends on factors such as its size, the amount and kind of lubrication in use, the cage and bearing materials, precision tolerances and levels, and what periods or lengths of time maximum speeds are required.

6) Do Higher ABEC Ratings Mean Quieter Bearings?

There is anecdotal evidence suggesting a correlation between noise and ABEC precision ratings. However, the correlation is loose, as higher ABEC ratings are not a guarantee of less noise. There are factors that determine noise that do not go into ABEC ratings, such as material quality, ball precision, and how smooth a rolling contact surface is. The kind of lubricant in use is also critical. A quiet grease can reduce running volume, but proper preloading, installation, and handling also help optimize quiet operation when possible.

7) What’s The Best Bearing Grease?

This is another variable answer. Application conditions often determine what might prove the best bearing lubricant, which can be grease or an oil. You can further break down options as natural, synthetic, microfiltered, and more. Each grease has its pros and cons in how it performs and has its own cost-efficiency or effectiveness. A ‘quiet’ grease might start breaking down at a high temperature, and a high-temperature grease usually can’t handle a high load as well as you’d like.

Last modified on December 22, 2017

Categories: Bearings

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