Dimensions (metric) Two Shields ZZ d 6 D 19 B 6 Approx. Wgt. lbs .0220 Interchange ADR W626ZZ ISC - NMB SSR-1960ZZ NTN F626ZZ RMB - SKF W626ZZ 1) Outer races, inner races and balls are manufactured from 440C or equivalent stainless steel. They are through hardened to a hardness of 55-57RC. 2) The cages are manufactured from 304 or equivalent stainless steel. 3) Shields are manufactured from 304 or equivalent stainless steel.