... C: forging, shaping, warm bending, high frequency shrinkage fitting, heat enveloping, heat sealing, metal desiccating, nut inserting, rotor inserting,etc.D: ... parts, sprockets, gauges, moulds, piston rods, etc HSS Heat TreatmentInduction HardeningHardening and TemperingGas CarburizingCase HardeningTougheningCarbo NitridingCore RefiningSpherodizingAnnealingNormalizingStress RelievingAus TemperingMar ...