... machine.c. We can do testing of hardness, salt spray test, coating and so on.SPECIFICATION:MATERIAL: LOW CARBON STEEL, C1045, AND ... OTHER MATERIAL REQUIRED BY PRINTS.FINISH: COMMON BLACK POWDER ... IN MAKING VARIOUS HINGES, IF YOU HAVE ANY SPECIAL REQUIREMENTS OF MATERIAL, FINISH, HARDNESS, PACKING AND SO ON, PLS GIVE US ...