Locking pins are small cylindrical devices that prevent a nut from turning when placed at the end. They prevent the nut from being released and come in different sizes, lengths and types, depending on the application.
Locking pins are commonly used to lock weights in gyms before using weight machines. These pins hold the nut in place until released, and variants such as lifting pins and ball lock pins cater to different applications. Positive locking pins use a push button to initiate ball action and retraction, and they are easy to fasten and remove. Double-ball lock pins are used for a firmer lock and to increase retention.