Spiral Torsion Springs are made from flat strip stock, wound on an arbor with a space between the coils. They generally have a lug of some sort across the I.D. of the spring, which engages a slot in the shaft, over which it works. However, the I.D. can be made with holes to engage an arbor protrusion or can be made in a special shape to fit over a similar shaped shaft. The outside end is only limited by the designers’ imagination.

A spiral spring delivers its force (torque) in a rotary motion and normally rotates less than one revolution. Deflecting more than one turn, results in the coils touching, which introduces friction between the coils, resulting in erratic force readings.

The highest stress point on this type of spring is the outside edge of the strip stock. To ensure springs of the highest quality, we only use material with a "skived" round edge or material rolled from round wire, which produces a natural round edge.

Spiral springs are used in applications where axial space is limited, such as brush springs in D.C. motors. They are used in many other applications as indicated on the Application Page.

Power Springs differ from Spiral Springs in that they deliver their torque through many revolutions of the arbor or shaft. Both springs are made of strip steel with formed or pierced ends, but the similarity ends there. Power Springs are made of pre-tempered steel and coiled into a case or retainer.

Depending on the end configuration, at times it may be necessary to anneal (soften) the ends so forming can be done without fracturing the material. This is generally necessary when very sharp bends or intricate end configurations are required.