Enduro Bearings 71801 LLB - ABEC 5 - Angular Contact Ball Bearing - 12x21x5mm

ABEC 5 angular contact bearing with 12 mm inner diameter, 21 mm outer diameter, 5 mm thickness and double-lip type sealing with light contact, making a labyrinth seal. In standard radial bearings, only 3 or 4 balls make contact during the load, at any given time. In Angular Contact (A/C) bearings, ALL balls are engaged and spread the force over a larger surface area, to decrease friction and minimize wear. ABEC 5 bearings use grade 5 Chromium Steel Balls and 52100 High Carbon Chromium Alloy Races. The 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. Vacuum de-gassing 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. Nylon with graphite retainers are virtually frictionless while providing constant lubrication. 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. C-3 Clearance Manufacturer item code: 71801 LLB Weight supplement: manufacturer spec