Use cotter pins to lock a castle nut or secure a clevis pin. A cotter pin is easy to install and remove and is commonly used to secure a wheel or machine component on an axle. A split pin has two long tines that are bent to hold it in place. Hairpin clips, also called r clips, are designed to slip on with no bending required. Keep Grainger cotter pins on hand for speedy maintenance and repair of wheels and rotary machinery.