Handan ShuangZi Metal Products Co., Ltd. Is a professional manufacturer of fastener, mainly including: self drilling screw, drywall screw ,hex bolt &nut, expansion bolt and thread rod. Established in 2005. Since its inception, Shuangzi always committed to the production and research of drilling screws. Our company registered and introduced the advanced equipment from Taiwan , and employed the top domestic designers for product process , such as hexagon-shaping、clipping、thread-rolling、carburize、zinc plated、washer machine、package etc. Every link strives for perfection and the best . More than ten years developing, Shuangzi products are sold to all over the country and export to Southeast Asia, Middle East, South America, Africa, Eastern Europe , Russia etc over 30 countries and regions.