Turnbuckle

Small turnbuckle (80 mm)

A turnbuckle, stretching screw or bottlescrew is a device for adjusting the tension or length of ropes, cables, tie rods, and other tensioning systems. It normally consists of two threaded eyelets, one screwed into each end of a small metal frame, one with a left-hand thread and the other with a right-hand thread. The tension can be adjusted by rotating the frame, which causes both eyelets to be screwed in or out simultaneously, without twisting the eyelets or attached cables.

Uses

The corner structure of a wrestling ring showing the attachment of the ring ropes to the ring post via the padded turnbuckles

Turnbuckles are most commonly used in applications which require a great deal of tension; they can range in mass from about ten grams for thin cable used in a garden fence, to thousands of kilograms for structural elements in buildings and suspension bridges.

Aircraft

Turnbuckles are widely used in aircraft. Biplanes may use turnbuckles to adjust the tension on structural wires bracing their wings. Turnbuckles are also widely used on flexible cables in flight control systems. In both cases they are secured with lockwire or specifically designed wire clips to prevent them from turning and losing tension.

Shipping

Turnbuckles are used for tensioning a ship's rigging and lashings. This device is also known as a bottlescrew in this context.

Sports

Turnbuckles find a popular use for tensioning the ropes in professional wrestling rings and boxing rings, where they serve as the attachment between the ring ropes and ring posts. The turnbuckles in these rings are covered with padding in order to protect the competitors. The turnbuckles come into particular play in professional wrestling where they are often put to use by participants as part of their offensive repertoire.

Entertainment Industry

Turnbuckles are used in nearly all rigging performed in the entertainment industry, including theatre, film, and live concert performances. In entertainment rigging, turnbuckles are more commonly used to make small adjustments in line lengths. This is generally to make a flown unit sit parallel to the stage. Another way a turnbuckle could prove helpful is with making vary minor height or angle adjustments.

See also

• Guy-wire
• Mechanical joint

External links

• "Special Hardware You Should Know About." Popular Science, December 1959, p. 169.
• Turnbuckle at Townley Drop Forge