uxcell M4x55mm Alloy Steel Hex Bolt Socket Head Cap Machine Screws 5pcs Drive Type: Hex Socket; Head Style: Socket Cap Head; Material: Alloy Steel Package Content: 5pcs x Socket Head Cap Screws; Product Name: Socket Head Cap Screws; Thread Size: M4x20mm/0.16"x0.8"(D*L) Weight: 28g; Main Color: Black Thread Pitch: 0.7mm; Total Size(Not Include Head): M4x55mm/0.16"x2.2"(D*L) Hex Socket Width: 3mm/0.12"; Head Size: 7x4mm/0.28"x0.16"(D*H)