What Are ABEC Bearings?

The ABEC scale is a system for rating the manufacturing tolerances of precision bearings. The system was developed by the Annular Bearing Engineering Committee or Council (ABEC) of the American Bearing Manufacturers Association (ABMA). The American Bearing Manufacturers Association was formerly known as the Anti-Friction Bearing Manufacturers Association. 

What Does ABEC Mean? 

The ABEC scale is a system for rating the manufacturing tolerances of precision bearings. The system was developed by the Annular Bearing Engineering Committee or Council (ABEC) of the American Bearing Manufacturers Association (ABMA). The American Bearing Manufacturers Association was formerly known as the Anti-Friction Bearing Manufacturers Association. 

Bearings rated under the ABEC system are typically called "precision bearings", and they are rated with a number from 1 to 9, with the higher number assigned to bearings manufactured against a higher standard of precision (high number = tighter tolerances = more expensive bearing). 

What Does Tolerance Mean? 

Tolerance is the amount of variation from an absolute exact measurement that is permitted during the manufacturing process. 

Other Bearing Rating Systems 

ABEC is only one system for rating bearing tolerances. The International Standards Organization (ISO) and the German National Standards Organization (DIN) use similar scales to rate the precision of bearings. In the ISO and DIN systems, a smaller number means a tighter tolerance and a larger number means a looser tolerance. This is just the opposite of the ABEC system. See the following table for equivalents.

ABEC ratings are only odd numbers, and start with ABEC 1:

ABEC 1 is the most crude, the least precise, the most durable and the cheapest.

ABEC 3 is what most cheap complete skateboards come with, especially skateboards from China.This [abec bearings] will work for most skateboarding, but won't roll very smoothly or fast.

ABEC 5 bearings are the norm in skateboarding. You get a reasonable amount of speed, and at a reasonable cost. However, there are lots of people who argue that the skateboarding industry is lying, and that most ABEC 5 skateboard bearings you see aren't actually built to ABEC 5 standards...

ABEC 7 bearings would be very fast and smooth, but very expensive. Plus, you start to run the risk of needlessly damaging them if you skate hard or aggressively. Also, if you are buying cheap ABEC 7 bearings made in China, you are probably being lied to (read The Truth about Skateboard Bearings.

ABEC 9 and higher bearings would be ridiculous to use in a skateboard, unless you are doing downhill luge style skating, or something else where your goal is to go insanely fast. If you aren't spending a fortune on these bearings, then don't trust that they are in fact ABEC 9!