To find the load at any working length, when the free
length, rate and initial tension are given, use the
formula: P= (R x F) + I.T.
where P is the load in lbs.; R is the rate in lbs. per inch;
F is the deflection from free length; I.T. is the initial
Example: (Lee Stock Spring Catalog #LE-031C-1) — Given a
free length of 1”, a rate of 6.9 pounds per inch, and
.7 pounds initial tension, find the load at 1.500”.
P = (6.9 x .500) + .7 = 3.45 + .7 = 4.15 lbs.