Steel ring 1) Material : carbon steel 2) Process: punching 3) Surface: black electrophoresis 4) OEM is available Steel RingMaterial : Carbon steelApplication : machinery,auto,home application,constructions, electronic etc.Surface :electrophoresis,znic-plated,plastic spraying,polishing ect Other kind of metal is availabe : aluminum,copper,stainless steel If you have any enquiry,please feel free to ...