... Materials: 20#, 45#, forge alloy steel (42GrMo,38GrMoAI), heating treatment and mechanical processing, hardness is HRC55~58. Advanced ... is HRC62 after polishing Inner structure: single-layer, multi-layer screw, Z and other structure.Processing: Chroming, Ceramic, Hard Chrome ... length is 6000 mm.Raw material is Carbon steel, alloy steel, stainless steel and others.Embossing roller, laser engravuring, ...