Threaded rod is a fastening bar or a rod threaded along its length. Thread direction is an important specification to consider. Choices include right hand, left hand, or both right hand and left hand. Right hand threads are configured so that clockwise rotation tightens the threaded rod to a fastener. Left hand threads are less common, but well-suited for applications in which motor vibration would cause right handed threads to loosen. When thread direction is not specified, the default direction is usually to the right. Left handed threads are usually listed explicitly. Threaded rod with both right hand threads and left hand threads have right threads at one end of the rod, and left threads at the opposite end. This dual thread style is used for specialty assemblies such as turnbuckles.