1.material: stainless steel. 2.surface: nickel,zinc,chrome . 3.standard: The Cap Nut is made by ISO,DIN,AISI,JIS. Item NameDIN985 HEX DOMED CAP NUTBrand NameZhongguMaterialCarbon steel ;stainless steel,brass,ect.Surface TreatmentZinc, copper, tin, nickel, ect.It can be environmentally friendly as your request.StandardDIN, ISO,DIN,JIS, BSW, ANSI or as your requestPortShenzhenAdvantageHigh quality ...