The main parameters: Material: SUM/12L14 free-cutting steel, 303/304 stainless steel, SUS420 series, etc. Hardness: HV550-650 HRC50-55 HRC26-32 Diameter tolerance: +0/-0.001MM Length tolerance: ±0.05MM Roughness: Ra0.08, Ry0.4 Common types and specifications: optical axis stepped axis flat position axis threaded axis