Gear Tooth Bending Stress (Lewis) Calculator

Calculate gear tooth bending stress σ = F_t/(b × m × Y) where Y = Lewis form factor, m = module, b = face width (8–16× module). Lewis form factor Y increases with number of teeth.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)
σy — Normal Stress Y (MPa)
τxy — Shear Stress (MPa)
⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.
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How to Use

Enter the values for the patient or scenario you are assessing. Calculate gear tooth bending stress σ = F_t/(b × m × Y) where Y = Lewis form factor, m = module, b = face width (8–16× module). Lewis form factor Y increases with number of teeth. Use the gear lewis stress result to inform your clinical assessment.

Frequently Asked Questions