... 4.OEM or ODM are welcome IFI156 blue zinc plating butterfly screws A. DIN316 Wing Screws Specification: 1 ... Surface treatmentPlain finish, black oxide, zinc plating(white, yellow, black colour), nickel plating, chromate plating, HDG, Dacromet, Geomet.5.Salt ... 1.Quality Certificate: ISO9001:2008, ISO14001:20042. Inspection quality system: ISO standard, 100% Whole range inspection through the production ...