Tension Springs/Extension Springs are helical wound coils, wrapped tightly together to create tension. Extension springs are springs which absorb and store energy by offering resistance to a pulling force. Extension springs usually have hooks, loops, or end coils that are pulled out and formed from each end of the body. The function of an extension spring is to provide extended force when the spring is pulled apart from its original length.
Compression Springs are designed to operate with a compressive load in “Push Mode”. Compression Spring also has variable pitch between coils which are used to reduce solid height, buckling and surging to produce nonlinear load deflection characteristics. Compression springs offer resistance to linear compressing forces and are in fact one of the most efficient energy storage devices available.
Torsion Springs / Helical Coils Springs are designed to operate with torque / twisting / rotary force. A torsion spring is a spring that works by twisting its end along its axis. When it is twisted, it exerts a torque in the opposite direction, proportional to the amount (angle) it is twisted.
Wire forms come in all sorts of shapes & sizes and each play different role. Wire forms are wires that have been bent into specific shapes, often to fulfil a particular purpose, one can commonly recognize wire form as a spring; though any shape that a wire takes is technically a wire form, other often seen wire forms include hooks and certain types of clips.