1.13 year experience, 2.Certificate ISO9001.2008, 3.Material: Bearing steel, 4.Various size ... : With two rows of balls; WIB, BWF, WS, WK, 885000 series, etc. 2) Ball-roller: With one row of balls, one row ... of rollers; WIR, WN, WKH, 665000 series, etc. 2 Material: Mainly the chrome Steel (GCr15) High-chrome steel, the ... bearings: Widely used in auto, machine,etc Water pump bearing WK series