[Flieger]

Originally Posted by winders

Torsion bars are also torsion springs. Look here:

Torsion Springs

Or here:

What Is a Torsion Spring?

Scott

Originally Posted by the website

Torsion Spring

A typical torsion helical spring is shown below. There are a wide variety of coil end configurations to suit different applications and a torsion spring is usually positioned on a shaft. The coils are usually close wound as are tension springs but they generally do not have any initial tension unlike tension springs.

The primary stress induced in torsion spring is a bending stress in the wire . This is not the case for the tension and compression helical springs for which the primary stress is a torsional (shear) stress. During forming residual stresses are built up in the winding process. These residual stresses are in the same direction but of opposite sign to the working stresses resulting when the spring is loaded causing the coils to tighten. Torsion springs are stronger as a result and they are often designed to work at, or above the yield strength.

This was my point.

It also brings up the point that coil springs are actually torsion bars!!