Skateboard bearings

Skateboard bearings must meet high requirements, such as the impact of tricks or lateral forces when turning. 

In short, they must be very resistant and durable.

The abbreviation ABEC stands for "Annular Bearing Engineers Committee" and is a standard for the precision with which rolling elements (that's what the balls in the bearing are called) are manufactured. The higher the ABEC rating, the lower the fault tolerance in the manufacturing of these components.

Since relatively low bearing speeds are achieved when skateboarding, the ABEC rating can be ignored.