Circlip
Encyclopedia
Fastener
A fastener is a hardware device that mechanically joins or affixes two or more objects together.Fasteners can also be used to close a container such as a bag, a box, or an envelope; or they may involve keeping together the sides of an opening of flexible material, attaching a lid to a container,...
consisting of a semi-flexible metal ring with open ends which can be snapped into place, into a machined
Machining
Conventional machining is a form of subtractive manufacturing, in which a collection of material-working processes utilizing power-driven machine tools, such as saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to physical remove material to achieve a desired...
groove
Groove (machining)
In manufacturing or mechanical engineering a groove is a long and narrow indentation built into a material, generally for the purpose of allowing another material or part to move within the groove and be guided by it. Examples include:...
on a dowel pin or other part to permit rotation
Rotation
A rotation is a circular movement of an object around a center of rotation. A three-dimensional object rotates always around an imaginary line called a rotation axis. If the axis is within the body, and passes through its center of mass the body is said to rotate upon itself, or spin. A rotation...
but to prevent lateral movement
Motion (physics)
In physics, motion is a change in position of an object with respect to time. Change in action is the result of an unbalanced force. Motion is typically described in terms of velocity, acceleration, displacement and time . An object's velocity cannot change unless it is acted upon by a force, as...
. There are two basic types: internal and external, referring to whether they are fitted into a bore or over a shaft. Circlips are often used to secure pinned connections.
Details
The clips are known as wrist pin clips or wrist pin retainers when used to retain piston wrist pins. Also known in UK as Gudgeon Pins, clips are therefore known as Gudgeon pin clips, when used to retain piston gudgeon pins. The most commonly used circlip for this application is a simple spring steel snap ring, or plain wire ring.Common examples include "E-clips" (e-ring
Retaining ring
A retaining ring is a fastener that holds components or assemblies onto a shaft or in a housing/bore when installed in a groove. Once installed, the exposed portion acts as a shoulder which retains the specific component or assembly....
) and the (both internal and external) snap ring or circlip.
This general type of fasteners are sized to provide an interference fit onto (or into, in the case of an internal fastener) a groove or land when in use, such that they must be elastically deformed in order to install or remove them.
Installation and lubrication
Since circlips are stamped out of sheetmetals there is a smooth side and a rough side. To prevent potential damage, circlips are installed with the smooth side facing the part and the rough side facing out. Wet or dry lubrication is required for the circlip to maintain its function.Circlips are designed to be removed with a special snap ring tool, but in field expedient situations, a pair of needle-nosed pliers or leverage with a flat-headed screwdriver are sometimes used.