... so on TypeSpecification (mm)MaterialTolerance ranges(mm)Hardness rangesRound tubeΦ5-Φ325Cr12M0V/SKD11Roundness:±0.0560-63HRCSquare ... wear resistance, toughness, resistance to high pressure, high hardness, hard quenching.10. Maching process: Raw materials- ... turning- drilling- turning- CNC precision turning- grinding- quenching- hardness test- internal and external grinding- test- boxing.11. Features ...