Shanghai Yiyuan International Trading Co., Ltd. lies in the center of the Shanghai financial district , is the headquarters of our Yihui hardware co.,ltd. is a factory based trading company with a wide range of hardware, include DIN 913 hexagon socket set screw,flat point;DIN 914 hexagon socket set screw,cone point;DIN915 hexagon socket set screw,dog point;DIN916 hexagon socket set screw,cup point;DIN906 Hexagon socket pipe plug; Hexagon socket set screw with knurled cup point; Slotted set screw;6-Lobe socket set screw;Hexagon socket set screw with oval point and all kinds of bolt etc.