Technical Definitions

What is ABEC ?

ABEC stands for Annular Bearing Engineering Committee of the AFBMA (Anti – Friction Bearing Manufacturers Association Inc.).

This committee set up standards for manufacturing “tolerances” (see definition of “clearance – tolerance - fit” ) of bearings. These standards are equal to the ISO (International Standards Organization), JIS (Japanese Industrial Standard), and DIN (Deutches Institut fur Normung) but with a different nomenclature.

1) ABEC – ISO / JIS / DIN equivalences

ABEC	1	3	5	7	9
ISO	P0	P6	P5	P4	P2
JIS	0	6	5	4	2
DIN	0	6	5	4	2

ABEC 1 is the lowest manufacturing tolerance (please see point 2 for examples of tolerances) and ABEC 9 is the highest. Most bearing manufacturers in the world comply with ABEC 1 standards.

2) ABEC Tolerances

The bearing tolerances stand for the dimensional accuracy and running accuracy.

The dimensional accuracy prescribes the tolerances necessary when installing bearings on shafts or in housings, and the running accuracy are the allowable limits for bearing runout during operation.

Example for tolerances of inner rings for ball bearings with bore between 0.6 and 2.5 mm, dimensions are in microns (0.001 mm – thousands of a millimeter).

Higher precision bearings are intended for high precision machinery to operate smoother and sometimes at higher speeds. These bearings are therefore a lot more expensive.

One market segment that is asking more and more for ABEC 5, ABEC 7 and even ABEC 9 bearings are the inline skaters. Here we have to say that everyone who is buying bearings higher than ABEC 3 is wasting its money, because after running 5-10 minutes or one jump, or cruising on asphalt (which is not a perfectly smooth surface), will have changed the higher tolerances to the lower ABEC 3 or even to ABEC 1 tolerances.

Our experience with bearings (more than 50 years in the market), has shown us that the performance in skating can be improved with:

- Lubricant type
- Quality of the bearing steel (stick to quality manufacturers)
- Internal and external clearance (see clearance – tolerance - fit)

where none of the above attributes are specified by ABEC grades

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800-225-4587 800-252-1996 (Fax)