Metal fasteners are hardware devices used to join or secure two or more objects together. Common types include screws, bolts, nuts, and washers. They are typically made from materials like steel, aluminum, or brass, which provide strength and durability. Metal fasteners are essential in various applications, from construction to automotive manufacturing. These fasteners come in different sizes and shapes to suit specific needs. For example, screws have a helical ridge that allows them to grip materials tightly, while bolts require a nut to secure them in place. Proper selection and installation of metal fasteners ensure structural integrity and safety.