Socket Cap Screws are reliable and durable and are used in many applications. They are available in a variety of head styles and materials. With a high cylindrical head, socket cap head fasteners have a recessed driving area and offer high hold power at high torque levels. Hex socket drive systems are driven by hex wrenches or power tools with hexagonal bits. A threaded fastener's size name includes information about the major external diameter, followed by the threads per inch, which indicates if it is coarse or fine. Coarse threads are better when working with brittle materials; they are sturdier and are easier to thread and unthread compared to fine. Coarse threading also allows for thicker coatings and platings. *****Disclaimer***** Picture is a representation of the product, for exact sizing please view the listing information for exact sizing. Partially Threaded screws may slightly vary in thread length based on manufacturer.