What is a turnbuckle? A turnbuckle is a rigging device that is used to adjust the tension and reduce slack in a rope, cable, or similar tensioning assembly. They are often used in the tensioning of fence or perimeter cables, suspension bridges or buildings, aircraft construction, or probably their most famous application tensioning the ropes in a boxing or wrestling ring. They consist of a body, a right-hand threaded end fitting, and a left-hand threaded end fitting. The end fittings can consist