Screw, Nut, Bolt manufacturer / supplier in China, offering Good Quality M3 M4 M5 M6 M8 M10 M12 Allen Key Hex Head Cap Screw Countersunk Socket Bolt DIN 7991, Black 10.9-Grade Carbon Steel DIN7991 Hex Socket Flat Head Machine Screw M3 M4 M5 Hex Socket Countersunk Head Screw, Factory-Direct 304 Stainless Steel DIN7984 Low-Profile Socket Screws – Precision-Machined, Fast Delivery for M3, M4, M8 Sizes and so on.