Automobile/engine "motorcycle"/bicycle/electric vehicle Material: SUS420J2/SUM24L/SUS300seriesSUS42J2/SUM24L/SUS300 Round tolerance: 0.0003mm Cylinder tolerance: 0.0005mm Surface roughness tolerance: Ry0.4 Gear, screw thread precision: Grade 6 Coaxial tolerance: 0.005mm Position tolerance: 0.03mm Heat treatment: Part hardening (cementite, oxidation, high frequency )total hardening