FAQ / How to measure a bearing?

How do I measure a bearing?

No vernier calliper? No problem, a ruler will do the job; however, it is recommended to use digital callipers as they provide the most accurate results.

Remember, most bearing sizes are full mm or inch sizes. eg: 9.53mm would be 3/8 inch.

If you measured at 9.5mm its probably an inch-sized bearing.

To measure the bore of a bearing, you can use a vernier calliper like the one shown. Insert the outer anvils of the calliper into the bore as shown and open the calliper until the bearing and calliper are a good fit about each other. Now read the value on the calliper. In the absence of a calliper, a good quality steel ruler will suffice.

To measure the outside diameter of a bearing, place the jaws of the calliper around the bearing and close it until it's a good fit but not tight; now read the value from the calliper.