Electronic Screw top material C1008-1022 high precise process zinc plated . Electronic Screw top material , high precise process and good packing , carbon steel ,(such as C1010 C1018 C1022 C1035 C1045 ) , stainless steel , brass , bronze and so on . Printer , Faxer etc. usually be in need of Electroninc Screw .black zinc plated , 3+ Chr. and meets ROHS standard.