Key / Keyway Capacity Calculator
Verify shear and crushing stress on shaft keys.
Ensure your key won’t shear off under load. This calculator checks both Shear Stress and Compressive (Crushing) Stress against the input torque. It supports both direct torque input or Power/RPM derivation.
1. Load Conditions
Nm
2. Key & Shaft Dimensions
mm
mm
mm
mm
Calculated Stresses
Shear Stress (τ)
—
MPa (N/mm²)
Crushing Stress (σc)
—
MPa (N/mm²)
Tangential Force (F)
— kN
Calc. Torque (T)
— Nm
Failure Modes & Formulas
Shear Failure
τ = F / (W × L)
Force divided by shear area (Width × Length).
Crushing Failure
σc = F / ( (H/2) × L )
Force divided by bearing area (Half-Height × Length).Typical Allowable Stresses
For standard low-carbon steel keys (e.g., C45, 1045):
- Allowable Shear: ~40-60 MPa (with safety factor)
- Allowable Crushing: ~80-120 MPa