A machine screw is a type of fastener designed to be inserted into a pre-threaded hole or paired with a nut for securing objects together. Unlike wood screws, which are tapered and designed to bite into wood, machine screws have a consistent diameter and are primarily used in metal applications.

A self-tapping screw is a type of fastener designed to create its own thread as it is driven into a material, eliminating the need for pre-drilling a hole. This feature makes them particularly useful for fastening materials like metal, plastic, or wood where tapping a pre-made hole may not be practical or possible.

A self-drilling screw is a specialized type of fastener designed to drill its own hole and tap its own threads as it is driven into a material. This feature eliminates the need for pre-drilling a hole, making them particularly efficient for fastening materials like metal, plastic, or wood.