Torsion springs are widely useful to store and release energy of
rotation or to maintain a pressure over a short distance. Our stock
selection includes torsion springs with four end positions, as
shown in the drawings on this page:
Torsion springs are normally used over a supporting mandrel or
arbor. Suggested mandrel sizes allow 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.
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.
Torque values listed are suitable for average conditions. These
values can be increased about 20% for static conditions with only
slight setting. Infinite fatique life can be expected under good
mounting conditions, using torque values about 20% less than those
For inspection purposes the load should be applied at the radius
listed. Using other radii may appreciably alter the active length
of wire and effect the test results.
The torque values listed can be translated to direct load by use
of the formula: P = T/R where P is the load applied at radius
Example: For part T012-090-055, what is the load when
P= T/R = 5.31 / 4.75 = 1.12 N
The torque values listed will be attained at the deflections
listed. Torque values at intermediate deflections can be computed
by direct proration. Example: For part T030-180-250, the torque at
90 deg. deflection is: 0.312 in/lb.