A fastener is a small tool that is designed to hold materials together, either temporarily or permanently. Some fasteners, like screws, are designed to fasten to complementary nuts via threads that are engineered to fit together and provide support for the structure of the material being secured. Others, like socket cap screws, are used to fasten directly to the material itself. The difference between socket cap screws and other types of screw is that socket screws have a built-in hexagonal internal drive, which requires the use of a special wrench called an Allen wrench (hex key) to install and remove them.

Socket cap screws come in a variety of styles, finishes and sizes. Some are cold headed and made of DFARS-sourced steel for extra strength, allowing them to handle more torque without stripping or breaking. Some have a projecting collar that acts like a washer, dispersing the load around the bearing surface to prevent the head from pulling through the material. Some are even able to withstand extreme temperatures and high-pressure environments.

Socket screws with a nylon patch or an Allen head provide a little extra locking strength to help prevent loosening due to vibration. Combined zinc-nickel plating offers more corrosion resistance than standard zinc alone. Lastly, there are also some varieties of socket screw with lower head heights to accommodate situations where the head could snag or clog moving machinery or equipment. They cannot withstand the same level of preload as traditional Socket Head caps, but they are ideal for applications with limited clearance.    Socket Screw