... #, 45#, forge alloy steel (42GrMo,38GrMoAI), heating treatment and mechanical processing, hardness is HRC55~58. Advanced heat treatment ... polishing Inner structure: single-layer, multi-layer screw, Z and other structure.Processing: Chroming, Ceramic, Hard Chrome plating ( ... making high accuracy cylinders Bridle . cylinders Bridle 3,750*6000mm,for hot fabric,3D pattern,laser engraving,made by Shanghai ...