... automobile, motorcycle parts. such as crank axles, tie rod, gudgeon pin, chain wheel, aluminium wheels, air door, ocher-arm shaft,drive ... all kinds of gear wheel, chain wheel, kinds of axis, pin.3. hardening the industrial of machine tool, such as : bed ... heat treatment pliers, spanner, screwdriver, drill, axe 5. hardening pin, piston ring, spring pin, valve, shifting fork. 6. all kinds of track spiker ...