... 45#, forge alloy steel (42GrMo,38GrMoAI), heating treatment and mechanical processing, hardness is HRC55~58. Advanced heat treatment ... Inner structure: single-layer, multi-layer screw, Z and other structure.Processing: Chroming, Ceramic, Hard Chrome plating ... steel, alloy steel, stainless steel and others.Embossing roller, laser engravuring, 3D design and others technology.Mirror roller, Ra is ...