A hairpin fastener, also known as a hairpin cotter or hairpin clip, is a U-shaped pin commonly used in various industries such as automotive and machinery manufacturing. With one end featuring an open loop and the other splitting into two straight prongs, hairpin fasteners are designed for securing components by passing the open loop through a designated hole or slot and hooking the prongs around another part. Their ease of assembly and disassembly, without the need for additional tools, makes them ideal for applications requiring frequent adjustments or maintenance. Hairpin fasteners provide a quick and secure connection, preventing unintended disengagement and contributing to the efficiency of assemblies. They are versatile, available in different sizes and materials, and are chosen for their simplicity and effectiveness in creating semi-permanent or temporary connections.