Haiyan gold hardware mainly produces six nut, flange nut, welding nut, square nuts, nylon lock nuts and other standard nuts and non-standard nuts and round, square, solid, head, drywall screws, self tapping screws, fiberboard screws, bolts etc.. All standards are involved: GB GB, international standard ISO, German standard DIN, American Standard ANSI, British standard BS, mark UNI, Japanese JIS, Australian standard AS