... 0.005~0.008Shrink fit : 0.012~0.0005mmMaterial: plastic (resin ),aluminum alloy(bushing),copper(bushing),steel(ball).Hardness: ... made of other material ,just like ceramic,plastic etc.)NO 1: Plastic bushing (blue,white colour,POMS,POMBS,POMM, ... ALM,ALBT,ALT type );NO 3:Copper bushing(copper-colored, CUS,CUM,CUT type).Also each type with the ... glad to give you the best service. POM plastic bearing in China