Socket Head Cap Screw
A special kind of screw, socket screws feature a built-in hexagonal internal drive and require a specific kind of wrench (an Allen or socket wrench) for installation. They’re commonly found in machine parts, die fixturing and clamping applications, and electronics. These screws are often finished with black oxide or zinc plating to provide corrosion resistance and a sleek, glossy appearance.
These fasteners can be used in a variety of confined spaces where standard hex screws and bolts won’t fit because they have a low-profile design, no protrusions to snag skin or clothing, and are recessed into the hole so that their head is flush with the surface it’s installed into. They’re also easy to install, tighten or loosen.
Often, these screws are made from metals that can be hardened through heat treatment to increase their strength and durability. They’re manufactured through a process of cold forming, thread cutting or rolling to create the threads, and heat treating to give them their hardness and tensile strength.
Socket head cap screws have a smaller diameter than other machine screw heads, usually about 1.5 times the thread diameter. These screws are rounded and have thick side walls that help them handle high amounts of force without losing their shape or failing.
These fasteners should always be properly installed to ensure that they don’t lose their strength or damage the components to which they’re attached. They should be inspected regularly for signs of wear or failure and replaced promptly when necessary.