... :15 days 4.OEM or ODM are welcome IFI156 blue zinc plating butterfly screws A. DIN316 Wing Screws Specification: 1.Screw StandardDIN316 ... need.4.Surface treatmentPlain finish, black oxide, zinc plating(white, yellow, black colour), nickel plating, chromate plating, HDG, Dacromet, Geomet.5.Salt spray time2 ...