Hex screws, also called hex head screws or bolts, are fasteners characterized by a hexagonal-shaped head designed to be tightened with a wrench or socket. They are widely used in construction, automotive, machinery, and DIY projects due to their durability and strong fastening capabilities. Hex screws are available in various materials like stainless steel, carbon steel, and alloy steel, making them suitable for different environments, including corrosive or high-stress conditions. They are preferred in applications requiring secure joints, such as in steel structures, wooden frames, or heavy machinery.

Hex screws are unique due to their six-sided head, which offers better grip and torque compared to screws with slotted or Phillips heads. This makes them ideal for high-load applications. Unlike some screws that might require specialized tools (e.g., a screwdriver), hex screws can be tightened using standard wrenches, sockets, or hex keys. Additionally, they are often more robust and versatile, available in various grades for specific applications, such as high-strength bolts for industrial machinery or weather-resistant ones for outdoor use.

Hex screws come in both metric and imperial sizes. Common diameters range from M4 to M20 in metric (4mm to 20mm) and from 1/4 inch to 1 inch in imperial. The lengths can vary widely, from a few millimeters to several inches, depending on the application. Size selection is crucial for ensuring compatibility and performance.