Socket Head Cap Screw
There are several different types of socket head cap screws, each designed for specific applications and industries. However, they all share the same basic design and are rated to withstand high-strength clamping forces. Unlike traditional hex bolts, most socket cap screws have a cylindrical head that sits at around 82-degrees of angle (imperial) or 90-degrees of angle (metric). The head is usually a little bit larger and more bulbous than other screw varieties, such as low or flat head.
These caps are designed to fit into a hex drive hole, which allows them to be easily turned and tightened using a standard wrench or socket. The screw is then threaded throughout its entire length, making it a high-strength fastener. Typically, the threads are cut or rolled, though some are forged from a special material. They can also be subjected to heat treatment or other processes to enhance their strength, corrosion resistance, and other properties.
Like other screw types, they are available in various materials, from DFARS-sourced steel for military projects to corrosion-resistant stainless for food and chemical processing. They can be made in a variety of finishes, as well.
Most often, they are plated with black oxide for a sleek appearance and increased corrosion protection. However, some are available in a bare or zinc plating for lower-cost options. They can also be manufactured from solid brass, which is highly resistant to corrosion in exposed environments or outdoor applications. Socket Head Cap Screw