Golden Speed Group is a diversified export-oriented enterprise integrated with technology, industry and trade. Yanwei Hardware Spring Factory, specialized in the production of springs, is the subsidiaries of Golden Speed Group in China. We are also a diversified, export-oriented enterprise integrated with professional spring design, production, sale, export, etc. We own independent import and export right. Our products sell all over the world, such as France, UK, America, Canada, Iran etc. Innovation: By virtue of Golden Speed Group, we are always aimed at innovation. Quality Control: The enterprise has fully implemented ISO 9001：2008 international quality management system. Production capacity: The enterprise has imported a series of CNC production and testing equipments from Taiwan, including 15 NC computers and 5 big CNC spring coilers. So it can professionally produce many kinds of springs, such as production materials between 0.1 mm and 60 mm, and can also produce large diameter(100-800mm) springs according to customer requirement. The enterprise has specializing in the production clock spring(scroll spring) production line, production materials : （0.1-4）×（3－60）mm . Supply capacity: The supply capacity of the enterprise is excellent by virtue of Shanghai Port, Ningbo Port and the International Trade City – Yiwu, as well as our logistics and production efforts. Therefore we are able to fully meet the customer needs, whether sent in China or all over the world. The Specification of spring: 1.75&＃039;&＃039; 2.0&＃039;&＃039; 2.625&＃039;&＃039; 3.75&＃039;&＃039; 5.25&＃039;&＃039; 6&＃039;&＃039; etc. Materials: DIN 17223, JIS G3522, GRS3522. Wire Diameter: ø4.0~ø***** series of door springs we developed are equal to the spring that made in Germany. Excellent quality, competitive price; high strength and long lifetime. The Surface Treatment: The common specifications (ID.): 1.75&＃039;&＃039;, 2.0&＃039;&＃039;, 2.625&＃039;&＃039;, 3.75&＃039;&＃039;, 6.0&＃039;&＃039;. Surface treatment contains anti-rust oil, Shot peented (kugelgestrahlt), Galvanised( white zinc, colored zinc), electrophoresis, common paint, automotive topcoat. We can use surface treatment method according to customer choice.