Several types of components may be referred to as spring clips, but typically the term applies to a Terry clip. These enable a cylindrical object to be rapidly attached and removed, by simply pushing it into the clip or pulling it out.
Spring clips, therefore, make ideal tool holders and are often used to hold hammers and screwdrivers on tool boards. They were initially used to hold a pump on the frame of a bicycle.
Typical spring clips are self-retaining, one-piece fasteners that slide into a mounting hole or onto a flange or panel edge. Secondary fastening devices such as rivets, studs or screws are not required because the clips are held in place by spring tension and cannot easily be loosened by vibration. The clips also compensate for tolerance build-up and misalignment.
The basic spring clip material is steel with 0.50 to 0.80% carbon. In general, fasteners are hardened to Rockwell C 45-50. By controlling the width and thickness of the steel, various spring tensions are achieved.
A Terry clip consists of a strip of spring-loaded sheet metal, usually steel, which is shaped into a profile. This has a flat base with a hole where the clip is semi-permanently screwed to a surface. Curved sides extend upward from each end of the base so that they can receive and grip a cylindrical object.
The sides then open to provide guides that can be used to inaccurately push objects into the clip.
Other types of clips sometimes referred to as ‘spring clips’ include:
Transistor clips or gull-wing clips: Small sheet metal clips which screw down onto a circuit board to clamp a transistor to a heat sink.
R-clips or R-pins: A sprung pin, which has a straight section, is bent to form a ring at the head and then has a curved section returning offset from the straight pin. The straight pin is designed to be pushed through a hole in a shaft, the curved section then clips around the outside of the shaft, retaining the pin in place. A finger can be inserted through the ring at the head to pull the pin out of the hole.
Linchpin: A pin with a separate ring attached. Used in similar applications to an R-clip. The pin is inserted through a hole in a shaft and the ring is folded over to prevent the pin from being removed. The ring has each end attached to the pin with an offset, causing it to stay clipped in the open or closed position. Linchpins are only suitable for use at the end of a shaft whereas R-clips may be used anywhere along a shaft.
Spring hose clamps: A clamp designed to hold a hose onto a spigot, serving a similar purpose to a jubilee clip, but allowing rapid attachment and removal. The resting position of the clamp has a smaller diameter than the pipe being clamped and two handles are squeezed together to increase the diameter to enable fitting and removal.