Socket Head Screw
A socket head cap screw, also known as a hex socket screw or Allen bolt, is a type of fastener used in applications where a standard nut and bolt isn’t possible. They have a cylindrical shaft that has a concave, hollow head that enables the screw to generate a compressive load. This helps to prevent rotational or lateral movement of the screw, and can stand up to vibration. The hex socket drive gives the screw six stress-bearing sides for use with an Allen wrench (or hex key) and allows it to resist cam-out better than most other types of drives.
These fasteners are typically made of alloy steel or stainless steel, but can be manufactured in a variety of other materials depending on the application requirements. For example, aluminium socket screws are ideal for lighter applications with lower limited side clearance. Brass socket cap screws, however, are often a preferable option for applications where corrosion resistance is an important factor.
Different varieties of socket caps screws are available with various heads and threads, which allow them to be used in a wide range of applications. Hex socket cap screws are a common variety, which has an internal hex drive hole for installation and tightening. Other head designs include low and button heads, which are intended for driving into countersunk holes. A 12-point flange head variant, sometimes called a flange socket cap screw, has an increased hex size and larger head, which is designed to fit into a wider range of applications and counterbored holes that are normally made for standard hex socket caps screws. Socket Head Screw