... wire to high-level precision steel ball.MAIN PRODUCTS:1. Stainless steel ball, with material AISI304, 316, 420C ... used in several industries, such as hardware, sliders, ball bearing lead screw, wheels, toys, bicycles, bearings, ... BallMaterialAISI440Size2.0 mmGradeG500Hardness ( HRC)HRC58-65ApplicationBicycle, bearing, pulley, slide, handcraft, shelf, luggage, hardware, grinding mediaStandardGB/T-308- ...