

GENERAL NOTES 
1. 
Lengths of legs are shown as A in sketches below. 
2. 
It is to be noted that R (radius in inches)
where force is applied is always 1/2 of A (Length
of Leg). Dotted lines of legs show loaded position
where values of T (Torque) will be achieved at
R (Radius). 
3. 
To translate torque values to direct load:
Use Formula P=T/R
P = Load applied at Radius (R)
T = Torque
Example: Part LTL 012A 01:
What is the load where R = .187?
Using P = T/R = .050/.187 = .267lbs. 
4. 
To calculate torque values other than those
listed (Position of Ends), a direct proportion may be used.
Example: Part LTL 012 A 01:
Torque shown in catalog listing is
.050 inlbs. for 90° deflection;
therefore, torque for 45° would be
.025 inlbs.

5. 
Inspection of Load Loads should always be checked at the Radius (R value)




SPECIFICATIONS 
Material
Music Wire
302 Stainless Steel
PLATING
Zinc Plated .0002
(ASTM B633)
Passivation:(ASTM A967)
(Mill Spec. No. QQP35)
Tolerances on Torque: ± 10%

Tolerances on Outside Diameter 
Inches
 Millimeters 
.093  .125  ± .004  2.36  3.17  ± .10mm 
.126  .200  ± .005  3.18  5.08  ± .13mm 
.201  .300  ± .007  5.09  7.62  ± .18mm 
.301  .410  ± .010  7.63  10.41  ± .26mm 
.411  .500  ± .013  10.42  12.70  ± .33mm 
.501  .700  ± .015  12.71  17.78  ± .38mm 
.701  .875  ± .020  17.79  22.23  ± .51mm 
.876  1.125  ± .025  22.24  28.58  ± .64mm 
1.126  1.218  ± .030  28.59  30.94  ± .76mm 
1.219  1.250  ± .035  30.95  31.75  ± .89mm 
Tolerances on Free Position: 
From 3 to 10 total coils (Incl.) ± 10° 
From 11 to 20 total coils (Incl.) ± 15° 

MANDREL SIZE 
Generally, torsion springs are used over a mandrel (shaftor arbor).
The column Suggested Mandrel Size, Inches,
allows approximately a 10% clearance for the various
deflections shown in examples below. If you require
greater deflections, we suggest a suitable reduction in the
mandrel size. 
DIRECTION OF WIND 
Good design dictates that torsion springs should be used
in the direction that winds the coil. When ordering be sure to choose either LTL (Left Hand Wound) or LTR (Right Hand Wound) for required application.

