Springs can be classified depending on how the load force is applied to them:
· Tension/extension spring – the spring is designed to operate with a tension load, so the spring stretches as the load is applied to it.
· Compression spring – is designed to operate with a compression load, so the spring gets shorter as the load is applied to it.
· Torsion spring – unlike the above types in which the load is an axial force, the load applied to a torsion spring is a torque or twisting force, and the end of the spring rotates through an angle as the load is applied.
· Constant spring - supported load remains the same throughout deflection cycle.
· Variable spring - resistance of the coil to load varies during compression
· Variable Stiffness spring - resistance of the coil to load can be dynamically varied for example by the control system,some types of these springs also vary their length thereby providing actuation capability as well.
Spring have its own languages:
Active coils (na): Those coils which are free to deflect under load.
Angular relationship of ends: The relative position of the plane of the hooks or loops of extension springs to each other.
Baking: Heating of electroplated springs to relieve hydrogen embrittlement.
Buckling: Bowing or lateral deflection of compression springs when compressed, related to slenderness ratio (L/D).
Closed ends: Ends of compression springs where pitch of the end coils is reduced so that the end coils touch.
Closed and ground ends: As with closed ends, except that the end is ground to provide a flat plane.
Closed length: see Solid height
Close-wound: Coiled with adjacent coils touching.
Coils per inch: see Pitch