left-hand thread

**left-hand thread**

A left-hand thread is a type of screw thread that tightens when turned counterclockwise (to the left), opposite to the more common right-hand thread. It is typically used in applications where rotational forces might otherwise loosen a standard right-hand threaded fastener. Common uses include bicycle pedals, gas fittings, and certain machinery components to enhance safety and reliability. Use the “left-hand thread” tag to categorize posts related to fasteners, mechanical engineering, and specialized threading techniques.