... .precision casting2.sewing machine parts3.mechanical part4.alloy steel part5.China1.precision casting2.sewing machine parts3.mechanical part 4.alloy steel part5.China Item ... machine.Heat treatmentannealing, termpering, quenching, normalizing, solid solution.Testing facilityspectrometer, tensile test machine, hardness test machine, mircoscope. China sewing machine parts,mechanical part,alloy steel ...