Enduro Bearings - Enduro ABEC5 bearing MR 163110 LLB 16x31x10mm 25.3g

Enduro ABEC5 bearing MR 2437 SRS 24x37x7mm 31.0g

Balls:
Grade 5 Chromium Steel Balls
High precision balls are within 5/1,000,000″ round. These are military level specification, used for precision equipment. R-64 hardness, of the highest grade.

Races:
52100 High Carbon Chromium Alloy Races
Vacuum de-gassed process for the purest chromium alloy steel, hardened to R-62, extremely tough and very durable. Polished to a mirror finish for ABEC-5 precision and noiseless movement.

Retainers:
Graphite/Nylon Ball Retainers
Nylon with graphite retainers are virtually frictionless while providing constant lubrication.

The ABEC-5 Standard:
To meet the ABEC-5 standard, bearing design must pass all tests, which include noise testing at high RPM, extremely close tolerances for I.D. and O.D., roundness of ball, trueness of the races and micro surface finishes of balls and races.

Seals:
Two NBR 70 rubber  SRS seals with an axial face type seal, this seal has a large contact surface area, while running very smoothly and freely. They are easily removable with a snap ring which hold them in place, making them easy to service.