Gear tooth-root permissible-stress factor, K_S,tot — ISO 6336-3

Total correction factor σ_FP/σ_F,lim = (Y_ST·Y_NT·Y_δ·Y_R·Y_X)/S_F for the permissible tooth-root bending stress in the ISO 6336-3 calculation.

✓ validated against legacyoriginal: /calculators/ks.htm

Stress correction factor, Y_STLife factor, Y_NT (N < 3e6 cycles)Relative notch-sensitivity factor, Y_δRelative surface factor, Y_RSize factor, Y_XSafety factor for tooth breakage, S_F

Total correction factor, σ_FP/σ_F,lim = (Y_ST·Y_NT·Y_δ·Y_R·Y_X)/S_F1.33

Method & references

ISO 6336-3: Calculation of load capacity of spur and helical gears — permissible root stress correction factors.

The computation is a literal port of the original client-side JavaScript from /calculators/ks.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.

Gear tooth-root permissible-stress factor, K_S,tot — ISO 6336-3 — Engineering ABC