Durable Material: The star knob handle is made of plastic. The long bolt is made of galvanized carbon steel, which is hard, not easy to break, rust-resistant and corrosion-resistant, and has a long service life. Screw-In Design: The handle hand tightening screw has a smooth surface, comfortable grip, clear and complete threads, and uniform force, providing reinforcement operation for your equipment. Easy to Use: These clamping screw knobs are good for replacing damaged knobs, and the hexagonal star handle is easy to rotate to adjust the tightness. No additional tools are required and it can be installed and removed manually. Application: Suitable for reinforcement and knob replacement of equipment such as machinery and electronic equipment, communication equipment, hardware, furniture, umbrella bases, rack mounting, woodworking clamps, workbenches, saw fences and drill presses. Main Color: Black Material: Plastic, Carbon Steel Exterior Finish: Zinc Pitch: 1.25mm Thread Size: M8 x 16mm / 0.31" x 0.63"(Dia*L) Head Diameter: 32mm / 1.26" Total length: 28mm / 1.1" Package Content: 8Pcs x Clamping Screw Knobs