##  [Clevis](/clevis-0) 

 Definition

A U-shaped mechanical fastening or linkage component engineered to accept a removable pin across its open end so two members are joined with a bearing-supported, removable pivot; designed and dimensioned to carry shear and bearing loads at the pin while constraining relative motion primarily about the pin axis.

 

 

 

 

 

 





## Principle

Principle

A clevis creates a pivot connection by concentrating load transmission through a removable pin; its correct function depends on matched clearances, pin retention, and sufficient pin/shear-bearing capacity rather than on the U‑section alone.

 

 

 

 

 





## Demonstration

Demonstration

Illustrative scenario → A control rod terminates in a clevis that fits over an actuator arm ear. Recognition: U-shaped body with aligned holes. Action: a pin is inserted and retained by a cotter or clip to allow rotation about the pin axis. Consequence: the rod and arm pivot freely while remaining reversibly connected; if the pin is omitted or undersized, the connection can separate or the pin can shear.

 

 

 

 

## Misapplication

Misapplication

Treating any U-shaped bracket as a clevis and assuming it will provide a secure removable pivot. The semantic error is equating shape with intended pin-bearing function; a U-bracket without designed pin retention, bearing surface, or correct clearances is not a functional clevis.

 

 

 

 

 





## Consequence

Consequence

Selecting a non‑clevis in place of a proper clevis, or failing to secure the pin, causes bearing overload, accelerated wear, misalignment, loss of the removable pivot function, and possible separation under load through pin shear or pull‑out.

 

 

 

 

## Reversal

Reversal

When the joint must be permanently fixed, when rotation about additional axes is required, or when angular misalignment exceeds the pin clearance, alternative elements (welded joints, spherical rod ends, or multi‑axis bearings) replace a clevis. Also, for certified lifting applications a shackle with specified ratings may be required instead of a clevis designed for linkage loads.

 

 

 

 

 





## Boundary

Boundary

Clearly within: a machined U‑shaped end with aligned, sized holes and a retained pin providing a reversible pivot. Boundary case: a U‑shaped bracket with a loose through‑hole but no retention method or inadequate bearing area—may look like a clevis but fails under load. Clearly outside: an integral ear or lug designed as a rigid attachment without a removable pin.

 

 

 

 

 





## Semantic Tension

Semantic Tension

Clevis ↔ Shackle — both are U‑shaped and use a pin, but a clevis is specified for mechanical linkages and bearing-supported pivots while a shackle is often a rated lifting connector with different retention and inspection requirements.

 

 

 

 

 





## Synthesis

Synthesis

A clevis is defined by function more than shape: it is a U‑form whose geometry, hole sizing, and retention provisions create a removable, pin‑based pivot that transmits shear and bearing loads while permitting rotation about the pin axis.