This equation computes the helical torsional stress.
The tensile strength of spring steel may be found as:
`S_"ut" = A/d^m`, where A and m are uniquely defined for American National Standards Institute (ASTM) materials:
The allowable stress `sigma` then for a spring of cold-drawn carbon steel then given by this equation as:
`S_y = sigma = 0.78 S_ut`
Tensile Strength Parameters A & mMaterial | ASTM | m | A |
---|---|---|---|
Music wire | A228 | 0.163 | 2060 |
Oil-tempered wire | A229 | 0.193 | 1610 |
Hard-drawn wire | A227 | 0.201 | 1510 |
Chrome vanadium | A232 | 0.155 | 1790 |
Chrome silicon | A401 | 0.091 | 1960 |