March 30, 2024
April 3, 2024
Show all



  1. Function: The primary function of a cotter pin is to prevent nuts, bolts, clevis pins, or other fasteners from loosening or falling out due to vibration or movement. It acts as a locking mechanism, ensuring that the fastener remains securely in place.
  2. Design: Cotter pins are typically made of metal wire and are bent into a distinctive “U” or hairpin shape. They have two tines or legs that can be inserted through aligned holes in the components to be secured. Once inserted, the tines are bent back or spread apart to prevent the pin from slipping out.
  3. Installation: Cotter pins are installed by inserting the straight portion of the pin through the aligned holes in the fastener and the corresponding component. The pin is then bent back or spread apart to secure it in place, creating a reliable and tamper-resistant connection.
  4. Types: Cotter pins come in various sizes and configurations to suit different applications. The most common types include straight, extended prong, and hairpin cotter pins. Straight cotter pins are used for general-purpose applications, while extended prong and hairpin cotter pins provide additional security and stability in high-stress or critical applications.
  5. Applications: Cotter pins are widely used in automotive, aerospace, construction, and industrial machinery applications. They are commonly found in steering and suspension systems, axle assemblies, brake systems, and various mechanical linkages where secure fastening is essential.