... treatment, (optional) 5.assembly, (optional)6.QC and package, 7.delivery. Material could be aluminium, brass, copper, iron, steel, ... , steel bar, brass block and magnesium block, ect.), or the material can be done by forging or extrusion, 2.machining, 3. ... welding, (optional) 4.surface treatment, (optional)5.assembly, (optional)6.QC and ...