Topic summary
Tuning peg
Extracted from the Wikipedia article Tuning mechanisms for stringed instruments.
A tuning peg in a pegbox is perhaps the most common system. A peg has a grip or knob on it to allow it to be turned. A tuning pin is a tuning peg with a detachable grip, called a tuning lever. The socket on the tuning lever fits over the pin and allows it to be turned. Tuning pins are used on instruments where there is no space for a knob on each string, such as pianos and harps.