... 2 ) Measuring & testing equipment: Projector , concentricity tester, hardness tester, roughness tester, torsion tester, tensile force tester,etc. 3 ) Material: Different kinds of stainless steel, Brass ... ) Measuring & testing equipment: Projector , concentricity tester, hardness tester, roughness tester, torsion tester, tensile force tester,etc.3 ) Material: Different kinds of stainless steel, Brass ...