... bearings, We can supply all kinds of water pump bearing ball-ball and ball-roller. With high-quality material and advanced technology, 1 ... rows of balls; WIB, BWF, WS, WK, 885000 series, etc. 2) Ball-roller: With one row of balls, one row of rollers ... -chrome steel, the hardness reaches 58-62HBC, the hardness of ball and roller reaches 61-65 HRC, and the hardness of ...