Spring Rate
| Item | Formula | Source / Standard |
|---|---|---|
| Spring rate | k = G * d^4 / (8 * D^3 * n) | GB/T 23935 cylindrical helical springs |
| Deflection under load | f = F / k | GB/T 23935 spring design |
| Shear stress check | tau = 8 F D / (PI d^3) * Kw | GB/T 23935 (Wahl factor Kw) |