Pins are small, slender fasteners used for securing or aligning materials in a temporary or permanent manner. Available in a variety of types, including dowel pins, cotter pins, and hitch pins, they serve specific functions ranging from precision fitting in machinery to securing clevises and hinges. Manufactured from materials like steel, stainless steel, or brass, pins are essential in mechanical assemblies, jewelry making, and DIY projects, offering strength and reliability in a compact form for diverse fastening needs.