Wire Diameter Range
Generally .008” to .375”. Call for other sizes.
Loops, hooks, extended hooks, assembled components.
Relative hook position controlled.
Extension springs develop proportionally more load, force or resistance for each unit the spring is extended from free length. This change in load per unit of deflection is the spring rate, once all coils are open. The amount of force required to just separate the coils from touching adjacent coils is the initial tension.
Extension spring load = Initial Tension (IT) + (spring rate x deflection)
Even a well designed spring has an elastic limit and will take a set if stretched beyond this elastic limit. Once a spring has taken a set it will support less load.