Gear Tooth Stress Calculator

Calculate bending and contact stress on gear teeth using Lewis beam strength and Hertzian contact per AGMA/SAE standards.

Input Parameters

Results

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Bending Stress
MPa
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Contact Stress
MPa
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Pitch Diameter
mm
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Est. Safety Factor
Note: AGMA 2001-D04 and SAE J1619 govern gear design. Case-hardened steel gears allow 400-500 MPa bending, 1200-1500 MPa contact stress. Safety factor > 1.5 for automotive transmissions.

Reference

Pitch Dia = Module × Teeth Tangential Force = 2 × Torque / Pitch_dia Lewis Y = 0.484 − 2.87/Z (form factor) Bending Stress = Ft × Kv / (b × m × Y) Contact Stress = sqrt(Ft × E / (2pi × b × rho_eq)) rho_eq = r1×r2 / (r1+r2) [equivalent radius]