Spring length .
Number of coils and/or pitch .
Initial loading when fitted, working load, and amount of movement under load .
Length of legs and angle to one another, when free and when under load .
Guide to Torsion Springs Specification
A. Wire Diameter
B. Spring length
C. Number of coils
D. Length of legs and angle to one another, when free and under load
E. Direction of coiling
F. Inside diameter. Allow for a decrease in diameter as the spring is wound up, to avoid it binding on the rod or spindle around which it operates.
G. Load at installed position and at operating position. Alternatively specify amount of deflection at any load.
H. Rate of load per unit of rotation
I. Stress relieving. Not all torsion springs require stress relieving.