... : 20#, 45#, forge alloy steel (42GrMo,38GrMoAI), heating treatment and mechanical processing, hardness is HRC55~58.2. ... compact, adhesion strong.4.Precision: temperature difference <= 1°C, heating transform <= 0.02mm, concentric <= 0.005mm.5.Application: ... roller, heating roller, cooling roller, woolen paper roller, rubber roller, ink proofer, knurling tool, chrome roller, teflon roller, ceramic roller ...