Package Included: 30 x socket head screws. Metric M4 screws,Thread Diameter: 4mm; Thread Length: 20 mm/0.79inch; Pitch Size: 0.7mm. The socket head cap screws are 12.9 Grade Alloy Steel which is becoming hardness and more stronger after heat treatment and with good feature of anti-oxidation, high temperature resistance, anti-corrosion. Socket cap screws are commonly used in machine parts, die fixturing, and clamping. The socket head enables driving where there is not sufficient space for wrenches or sockets. Socket cap screws are high-hardness that is widely used in home, industrial, laptops,3D printer and 3D printed projects. Size Name:M4-0.7 x 25mm Thread Diameter: 4 mm Head Diameter: 7 mm/0.28inch Head Height: 4 mm/0.16inch Screw Length: 25 mm/0.98inch Grade：12.9 Surface treatment: black oxidation High Quality Material Alloy Steel Package Included 30 x Socket Head Cap Bolts/Screws Quality assurance, please rest assured to buy, if there is any problem, you can return or exchange