This secure yet removable general purpose threaded fastener is designed for insertion in pretapped holes or for use with nuts. Hex-head cap screw is a small but critical part that helps keep your production running smoothly. It features a thick, hexagonal head with a washer face under the head to provide an ample bearing surface for tightening with a wrench. Finding the right screw for your project is essential. Minimum thread length is calculated using the screw’s length. The formula is dia. X 2 + 1/4”.