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, Hexagon Socket Countersunk Head Screw Flat Head Socket Screw DIN7991 and so on.