A clevis fastener is a two-piece fastener system consisting of a ''clevis'' and a ''clevis pin head''.

Terms

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 ''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 (fastener), bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. The term also appl ...

,'' although a clevis and pin is only one of the many forms a shackle may take.

Usage

Clevises are used in a wide variety of fasteners used in

farming Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...

equipment and sailboat

rigging Rigging comprises the system of ropes, cables and chains, which support and control a sailing ship or sail boat's masts and sails. ''Standing rigging'' is the fixed rigging that supports masts including shrouds and stays. ''Running rigg ...

, as well as the automotive,

aircraft An aircraft ( 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 the Lift (force), dynamic lift of an airfoil, or, i ...

and

construction Construction are processes involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the a ...

industries. They are also widely used to attach control surfaces and other accessories to servo controls 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 (US usage) or split pin 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. A bolt can function as a clevis pin, but a bolt is not intended to take the lateral stress 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. The shearing strength of a threaded bolt is determined by its inner thread diameter. Clevis pins should be closely fitted to the holes in the clevis to limit wear and reduce the

failure rate Failure is the social concept of not meeting a desirable or intended objective, and is usually viewed as the opposite of success. The criteria for failure depends on context, and may be relative to a particular observer or belief system. On ...

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 animals 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.

References

{{Sail Types Fasteners