Fastening devices are used to hold two or more pieces together and are used on nearly every manufactured product, from toys to furniture to transportation vehicles. Many fasteners include screw threads, which are a form of helix and are manufactured in accordance with national and international standards. Fastening devices that do not use screw threads include pins, keys, rivets, and friction devices such as clips. This chapter is an introduction to the different types of fastening devices, their specifications, and their graphic representation.