Torsion springs

SPEC torsion springs are widely useful to store and release energy of rotation or to maintain pressure over a short distance. Our stock selection includes stainless steel torsion springs with four end positions, and music wire springs with three end positions as shown in the drawings.Spec torsion springs should be used in the direction that winds the coils. In the unwinding direction the maximum load is lower because of residual stresses. SPEC torsion springs are normally used over a supporting mandrel or arbor. Suggested mandrel sizes allow about 10% clearance at the deflections listed. If greater deflections are used, the arbor size should be reduced. Sufficient room (minimum axial space) must be provided in the assembly for the spring to function properly. Torque values listed are suitable for average conditions. These values can be increased about 20% for static conditions with only slight setting. To determine the load at any working length use rate proposed deflection. For inspection purposes, the load should be applied at 1/2 leg length (E). Using other lengths appreciably alters the active length of wire and affects the test results. The reference torque values listed can be translated to the approximate direct load by use of the formula P=T/En where P is the load applied at the new length En. Torque values at intermediate deflections can be calculated proportionally.

Stainless steel: Type 302 as per ASTM A313 or AMS 5688 spring temper
Music wire: ASTM-A228 or AMS 5112
Direction of Helix
Must be specified by adding a suffix to the catalogue number. Use L for left-hand wound or R for right-hand wound. See illustration:
Outer diameter       ±5% stainless steel
                              ±2% music wire
Straight torsion ends are standard.
Plain finish is standard. Allow additional time for special finishes.