uxcell M8x40mm Button Head Hex Socket Cap Screw Bolt Black 20pcs Drive Type: Hex Socket; Head Style: Button Head; Material: 10.9 Alloy Steel Package Content: 20pcs x Button Head Screws; Product Name: Button Head Screws Thread Size: M8x40mm/0.3"x1.6"(D*L); Weight: 310g Thread Pitch: 1.25mm; Total Length: 44mm/1.73" Hex Socket Width: 5mm/0.2"; Head Size: 14x4mm/0.55"x0.16"(D*H)