Bolts are a type of threaded fastener used to assemble two components together, often with the aid of a nut. Suitable for use with many types of materials, they come with a large variety of head designs in order to engage with the implement used to tighten them. Some head designs are also intended to lock in place, with a device just required for the other end. Bolts are made from a range of metals as well as nylon, and are built to form a firm and lasting hold in a wide variety of jobs indoors or out. A choice of shapes, thread designs, strengths and finishes is available in order to find the best match for all fastening tasks.