S: Stress
P: Load
D: Mean Diameter
d: Wire Diameter
Kw1: Wahl factor for 2% set point or fatigue
Kw2: Wahl factor for springs with set removed
C: Spring Index. The preferred range is 4-12
OD: Outside Diameter
| S | ||
| OD | ||
| C | ||
| Kw1 | ||
| Kw2 | ||
| P | ||
| d | ||
| D |
Spring Manufacturers Institute
Encyclopedia of Spring Design
Compression, Extension, Garter, and Torsion Springs