pan head quincunx groove triangular teeth self tapping screw self extrusion locking screw-尊龙凯时网娱乐官网

• product description: pan head hexagon screw, also referred to as hexagon bolt, cup head screw, hexagon screw, its name is not the same, but the meaning is the same. there are 4.8, 8.8, 10.9 and 12.9 in common use. also kn