A clevis fastener is a two-piece fastener system consisting of a ''clevis'' and a ''clevis pin head''. The clevis is a U-shaped piece that has holes at the end of the prongs to accept the clevis pin. The clevis pin is similar to a bolt, but is either partially threaded or unthreaded with a cross-hole for a

split pin A split pin, also known in the United States of America as a cotter pin or cotter key, is a metal fastener with two tines that are bent during installation, similar to a staple or rivet. Typically made of thick wire with a half-circular cross ...

. A ''tang'' is a piece that is sometimes fitted in the space within the clevis and is held in place by the clevis pin. The combination of a simple clevis fitted with a pin is commonly called a

shackle A shackle (or shacklebolt), also known as a gyve, is a U-shaped piece of metal secured with a clevis pin or bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. The term also applies to handcuff ...

, although a clevis and pin is only one of the many forms a shackle may take. Clevises are used in a wide variety of fasteners used in

farming Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peopl ...

equipment and sailboat

rigging Rigging comprises the system of ropes, cables and chains, which support a sailing ship or sail boat's masts—''standing rigging'', including shrouds and stays—and which adjust the position of the vessel's sails and spars to which they ar ...

, as well as the automotive,

aircraft An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...

and

construction Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and ...

industries. They are also widely used to attach control surfaces and other accessories to

servo control Servo control is a method of controlling many types of RC/hobbyist servos by sending the servo a PWM (pulse-width modulation) signal, a series of repeating pulses of variable width where either the width of the pulse (most common modern hobby ser ...

s in airworthy model aircraft. As a part of a fastener, a clevis provides a method of allowing rotation in some axes while restricting rotation in others.

Clevis pin

There are two main types of clevis pins: threaded and unthreaded. Unthreaded clevis pins have a domed head at one end and a cross-hole at the other end. A cotter pin (USA usage) or

is used to keep the clevis pin in place. Threaded clevis pins have a partially threaded shank on one end and a formed head on the other. The formed head has a lip, which acts as a stop when threading the pin into the shackle, and a flattened tab with a cross-hole. The flattened tab allows for easy installation of the pin and the cross-hole allows the pin to be

moused moused is a mouse daemon on FreeBSD systems that works with the console driver to support mouse operations in the text console and user programs. It first appeared in FreeBSD 2.2 and is currently located in /usr/sbin/moused. Function The mouse ...

. A bolt can function as a clevis pin, but a bolt is not intended to take the lateral

stress Stress may refer to: Science and medicine * Stress (biology), an organism's response to a stressor such as an environmental condition * Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...

that a clevis pin must handle. Normal bolts are manufactured to handle tension loads, whereas clevis pins and bolts are designed to withstand shearing forces. Clevis pins should be closely fitted to the holes in the clevis to limit wear and reduce the

failure rate Failure rate is the frequency with which an engineered system or component fails, expressed in failures per unit of time. It is usually denoted by the Greek letter λ (lambda) and is often used in reliability engineering. The failure rate of a ...

of either the pin or the clevis.

Twist clevis

A twist shackle provides a loop at a right angle to the axis of rotation. Older farming implements intended to be pulled by a team of

draft animal A working animal is an animal, usually domesticated, that is kept by humans and trained to perform tasks instead of being slaughtered to harvest animal products. Some are used for their physical strength (e.g. oxen and draft horses) or for ...

s often require a twist shackle to be hitched.

Clevis hanger

A clevis hanger consists of one U-shaped clevis and a second V-shaped clevis with a hole in a flattened section at the base of the V, joined together with a bolt or pin. Clevis hangers are used as a pipe attachment providing vertical adjustment for pipes.Pipe Supports - Glossary Terms
Piping Technology and Products (retrieved February 2012)

Clevis bracket

A clevis bracket generally takes the form of a solid metal piece with a flat rectangular base, fitted with holes for bolts or machine screws, and two rounded wings in parallel forming a clevis. Commonly used in aircraft and cars, clevis brackets allow mounting of rods to flat surfaces.

Clevis hook

A clevis hook is a hook, with or without a snap lock, with a clevis and bolt or pin at the base. The clevis is used to fasten the hook to a bracket or chain.

Clevis rod end

A clevis rod end is a folded or machined piece formed into a clevis and fitted with a hole at its base to which a rod is attached. In machined pieces, the hole is most often threaded.

Twin clevis

A twin clevis is a solid piece with two clevises directly opposite one another, each fitted with a pin. Twin clevises are commonly used to join two lengths of

chain A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. ...

References

{{Sail Types Fasteners Sailing rigs and rigging