... hexagaon flange head self tapping screwA: SpecificationMaterial:stainless steel,copper,alloy steel,aluminum,copper,carbon steelSurface Finish:nickel plated,white zinc,black zinc ... , Al6063 etc7,.Carbon steel:C1006,C1010,C1018,C1022,C1035K,C10458, Alloy steel: SCM435,C10B21,C10B33Specification& gaugeM4-M33Surface FinishingZn- Plated,Ni-plated ...