Reading bearing numbers: a field guide
What the digits and suffixes on a rolling bearing usually mean, and why you should still measure it.
The basic series code
Many metric ball bearings follow a pattern where the leading digits indicate the type and series and the final two digits relate to the bore. Conventions vary between manufacturers, so treat this as a guide.
Suffixes matter
Suffixes describe seals or shields, internal clearance, cage material and precision. Two bearings with the same base number can behave very differently.
Always confirm by measurement
Measure bore, outside diameter and width and compare with the manufacturer's catalogue before ordering.