**20pcs M8 Alloy Steel 12.9 Grade Hex Socket Cap Screws - Black Oxide - for Automotive & Machinery**

✔ Meets/exceeds: DIN 912 ✔ Screw Head Style: Socket Cap, Head Diameter 13.2 mm, Head Height 8.0 mm; Screw Drive Style: Internal Hex Drives, Known as Hex Socket Drives, Hex Size: 6.0 mm ✔ Material of Screws: Alloy Steel 40Cr, Black Oxide Finish; Strength Grade of Screws: 12.9 Grade, Hardness: HRC 39-44, Tensile Strength: 1220 N/mm² ✔ Rust proof of screws: black oxide finish with anti-rust oil ✔ Easy to store: these screws come in an easy-use storage case [ Sizes ]-----[ Thread Length ]-----[ Total Length ] M8 x 40 ------ 40 mm/1.57"------- 48 mm/1.89" M8 x 45 ------ 45 mm/1.77"------- 53 mm/2.09" M8 x 50 ------ 50 mm/1.97"------- 58 mm/2.28" M8 x 55 ------ 55 mm/2.17"------- 63 mm/2.48" M8 x 60 ------ 60 mm/2.36"------- 68 mm/2.68" [ Package Contains ] M8 x 40------4 Pcs M8 x 45------4 Pcs M8 x 50------4 Pcs M8 x 55------4 Pcs M8 x 60------4 Pcs [ About Internal Hex drives ] Internal Hex drives, also known as Hex Socket Drives, have a hexagonal hole in the center that requires an Allen key, also known as a hex key or Allen Wrench [ About Socket Cap Head ] Socket Cap Head , also known as Allen head , have a recessed drive, and are commonly used when there is not enough clearance for a conventional wrench or socket. They are fastened with an Allen wrench, which is also called a hex wrench or hex key