... %QC Detail Feature: steel spline gear shaft for car gearbox Product Name: steel gear shaftMaterials: grey iron, ductile ... lathe, line cutter etc.7. Testing equipment (foundry used): elongation tester, hardness tester, metallographic microscope, spectrometer, ... , chemistry composition analysis room. Testing equipment (machine shop used): vernier caliper, depth caliper, micrometer, depth micrometer, ...