A2 and A4 stainless steel left-hand hex nuts are used in applications requiring a left-hand threaded connection. Unlike a conventional right-hand thread, a left-hand nut is tightened counterclockwise. On rotating components, left-hand threads can be used where the direction of rotation could otherwise tend to loosen a right-hand nut – with the appropriate direction of rotation, the movement instead tends to tighten the nut. The range includes metric left-hand hex nuts for machinery, rotating equipment and other engineering applications where left-hand threads are combined with requirements for corrosion resistance. A2 and A4 provide material options for different applications and environmental requirements.