In article ,
says...

"Ned Simmons" wrote: And to carry this a bit further, the wire in a typical
torsion spring is primarily subject to bending, i.e., it's a coiled up
beam.
^^^^^^^^^^^^^
Let's unscramble this a little. A "torsion spring" is an elastic bar
subject to twisting--not bending. A "coil spring" is a torsion spring that
has been wound into a helix for compactness. A "leaf spring" is a beam in
bending.


A torsion *bar* is an elastic bar subject to twisting, a torsion
*spring* is a helical beam - like this...
http://www.sterlingspring.com/torsion_springs.html

Or a beam coupling...
http://www.bervina.com/kpl/special.html

Ned Simmons