For design engineers working with torsion springs the most challenging obstacle is how to transfer the torque through the spring. The Heli-Cal Machined Spring® solves this problem by machining attachment features into a single piece component, which allows a pure moment to be applied. By incorporating these symmetrical features into the machined spring the difficulty of applying torque to a traditional wire-wound spring is solved. Heli-cal Machined Springs can be manufactured in most machinable alloys including titanium, Inconel, MP-35N(r), dielectric materials, and maraging alloy steels. More information at Helical Products Machined Springs Site.