Screws – screws are mechanical fasteners that use external threads to directly secure objects together. They are a versatile tool as they are simple to use, generally do not require additional parts, and come in a huge assortment of types and sizes.

Nails – Nails are different from threaded fasteners as they contain no threads and fix two objects together rigidly by driving through one object and into the other. Nails come in many lengths, diameters, and shapes for unique applications.

Bolts/Nuts/Washers – Bolts are threaded fasteners which, when paired with a nut and a washer, will clamp two objects together that share same-sized drilled holes for the bolt to pass through. They are unlike screws in that bolts generally need additional nuts and washers, and their threads do not dig into the object and instead are used to generate the clamping force of the bolt-nut-washer assembly.

Rivets – Rivets are permanent joining tools but are still considered fasteners as they use mechanical force to clamp two objects (typically metal plates or sheets) together. Rivets are prolific in their uses, size, and shape, and are regarded as one of the most reliable fastener types

Even with this overview, there are still many, many fasteners out there that land in between each of these categories or form their own fastener type not shown here. It goes to show just how simple, varied, and integral they are to the thousands of applications of which they are a part.