Thin Section Bearings: Slim Yet Strong 

A radio telescope at dusk. Thin section bearings show up in observational equipment like this. Photo by Donald Giannatti.

Photo by Donald Giannatti

As part of our Bearings 101 series of informational articles, we’re highlighting types of bearings or bearing components. Today’s article is all about thin section bearings. 

The elegant thin section bearing might look dainty, but don’t let its slender proportions fool you. The thin section bearing punches above its weight while fitting into tight spaces. 

This bearing’s defining quality is its fixed cross-section. Thin section bearings in the same line all have the same thickness, regardless of bore diameter. At large diameters, these bearings are proportionally thin, hence their name.  

Engineers often choose thin section bearings for aerospace, robotics, and medical systems. Their light weight and small footprint at all diameters make them ideal for jobs with space and weight limits. Thin section bearings also keep parts turning smoothly for food processing, machining, textile manufacturing, and more. 

It takes great precision to make thin section bearings, so they often cost more than standard bearings – but the flexibility their thinness brings is worth the expense. Plus, they’re more resistant to moment load than similarly sized standard bearings. 

There are three contact styles for thin section bearings. 

  • Angular contact thin section bearings have the greatest thrust capacity of the thin section bearings. They have a 30-degree contact angle and two-thirds complement of balls, and need to be mounted opposing another bearing to establish the right contact angle. 
  • Four-point contact thin section bearings’ special gothic-arch-shaped raceway touches balls in four places. Four-point contact bearings can carry radial, axial, and moment loads simultaneously. A single four-point contact bearing can often replace two bearings, simplifying designs.
  • Radial contact thin section bearings are single-row and have Conrad-type assemblies. Their inner race is eccentrically displaced within the outer race, letting it hold about half a full complement of balls. It handles radial load best but can accept some axial load. This is the most popular type of thin section bearing. 

For more detailed descriptions of these types, read Alpine Bearing’s thin section bearing page. 

For help choosing a bearing type, advice about your specific application of thin section bearings, or to order thin section bearings, contact one of our sales engineers. 

Have you seen our other Bearings 101 articles? Here are our pieces on roller bearings, Thinex and torque tube bearings, machine tool spindle bearings, deep groove bearings, a comparison of bushings to bearings, and our bearing glossary. 

What bearing-related subject would you like to read about? Let us know by email, phone, or by using the chat feature on our website.