How To Identify Bearings — And Why It’s Important

How To Identify Bearings — And Why It’s Important

In an industry where technology is constantly advancing, best installation and maintenance practices of the parts that keep our applications functioning day-to-day, often get overlooked.

That’s why we’re going back to the basics. With the help of  this easy guide, you’ll soon be able to better Identify Bearings in your own workplace.

At the heart of any industrial business, bearings are working hard to keep essential applications and equipment up and running. While their role isn’t too elaborate, the shaft support they provide that allows for the free rotation of moving parts, while reducing friction between the moving and stationary components, is essential.

Being able to identify bearings is a worthwhile skill set for any industry member” Tim Zerger, Group Director of Bearings and Power Transmission at IBT, said. “If a customer comes in and knows what kind of bearing they already have, we can take its measurements and give you an exact part number.” One thing to keep in mind, though, according to Zerger, is that most bearings are measured in metric units – millimeters, not inches.

With the production efforts of countless industries and machines, comes countless bearing styles to accommodate them, each engineered specifically for the job required. There are many factors that influence the design of a bearing: load type, speed, temperature, shock or vibration, dirt or abrasive contamination, possible alignment inaccuracies, space limitations or shaft rigidity requirements. However, our first step in learning how to identify bearings is classifying them as either: Plain (Sleeve) Bearings or Rolling Bearings.

Identify Bearings-sleeve bearings

Plain (Sleeve) Bearings

Sleeve bearings, both mounted and unmounted, are the oldest style of bearings. They are found in automobiles, home appliances and all types of machinery that operate with lighter loads and at lower speeds. While they come in many sizes and shapes, each functions as a band of close fitting material that encloses and supports a moving member, or forms a “sleeve” around the shaft. The bearings generally maintain a thin film of lubricant between themselves and the shaft to reduce the friction that builds as a result of their interaction.

Rolling BearingsIdentify Bearings-rolling bearings

Rolling bearings, both mounted and unmounted, incorporate both ball and roller bearings, where the rotating members are separated from the stationary members by balls or rollers. This style of bearing is composed of one or two rows of steel balls or rollers between inner and outer rings and spaced out by a retainer. Grooves or raceways are cut into the inner and outer rings to guide the rolling element.

These are the most common, yet diverse, bearing family. Therefore, there are five primary categories to know when you identify bearings: radial ball, cylindrical roller, spherical roller, tapered roller and needle bearings. 


Deep Groove, Conrad Bearing
  • High degree of conformity between balls and raceways – deep groove and full shoulders
  • Single or double row designs
Identify Bearings-Conrad Ball Bearing
The Filling Slot, Max Type Bearing
  • Filling slot allows for the maximum number of balls directly between the rings
  • Single or double row designs
Identify Bearings-Max Bearing
Angular Contact Thrust Ball Bearing
  • Asymmetrical design – one shoulder is relieved or higher than the other
  • Has raceways in one or both of the rings
  • Usually mounted in opposing pairs either at the end of the shaft, face-to-face or back -to-back or in tandem
  • Single row, double row or four-point contact designs
Identify Bearings-angular-contact
Self-Aligning Ball Bearings
  • Generally has two rows of balls in a common outer ring raceway that share a common cage
  • Inner ring is mounted on rotating shaft and double-grooved to hold each row of balls separately
  • The outer ring raceway is spherical and accommodates for the changed travel pattern of the ball elements, providing the self-aligning feature
Identify Bearings-self-aligning-ball-bearing


  • Cylinder shaped rollers are kept evenly spaced by a cage, which guides their turning movement on the flat surface of the two races
  • The flanged ring, either inner or outer, with the roller and cage assembly, forms a unit which can be separated from the other for easy mounting
  • Surface of the rollers is slightly relieved or crowned at the ends, ultimately reducing stress and fiction.
  • Single, double or multi row designs
Identify Bearings-Cylindrical Roller Bearing


  • Has two rows of rollers that run on a common sphered raceway in the outer ring
  • Internally self-aligning, due to curved raceways and barrel-shaped rollers
  • Inner ring raceway is inclined at an angle to the bearing axis
  • Barrel-shaped rollers are guided by the inner ring raceway, the cage and in most cases, a non-integral guide ring positioned between the two rows of rollers
Identify Bearings-Spherical-Roller-Bearing


  • Angular lines formed by the tapered roller surfaces meet at a common point on the bearing axis, referred to as the apex point
  • Inner ring, rollers and cage are a non-separable assembly called the cone assembly, or simply, the cone
  • The outer ring, which is completely separate from the cone, is called the cup
  • Usually mounted face-to-face or back -to-back
Identify Bearings-Tapered Roller Bearing


  • A variation of the cylindrical bearing, except rollers are smaller in diameter and there are more rollers per bearing
  • In some styles, there is no cage holding everything in place. This bearing handles more load at slower speeds
  • In other styles, a retainer keeps the rollers separated, for the purpose of handling higher speeds and lighter loads
  • Rollers turn directly on the shaft, with or without an inner ring, accommodating for limited space situations
  • Available in single or double row designs
Identify Bearings-NeedlebearingIdentify Bearings-Precision-Needle-Roller-Bearings


IBT Industrial Solutions was founded in 1949 with Industrial Bearings in mind. Since then, we have become a trusted source for industry knowledge and expertise when it comes to bearings. When you partner with IBT, you’re guaranteed access to the best service and brands in the business.

Looking for more information on how to identify bearings? Contact our team of experts!

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