ABEC 3 radial double row bearing with 21.5 mm inner diameter, 31 mm outer diameter, 14 mm thickness and double-lip type sealing with light contact, making a labyrinth seal.
ABEC 3 bearings use grade 10 Chromium Steel Balls and 52100 High Carbon Chromium Alloy Races.
The high precision balls are within 10/1.000.000″ round, twice as round as the industry standard, at it's highest level.
The alloy races are made from a 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-3 precision and noiseless movement. The riveted Steel Retainer stands for toughness, ABEC-3 tolerances and noise tested, C-3 or C-N Internal Clearance.
Manufacturer item code: DR 21531 SW
Weight supplement: manufacturer spec