Interference Fit Calculator

Calculate minimum interference for torque transmission and maximum allowable interference before plastic deformation.

Hub Outer Diameter da

Interface Diameter df

Shaft Bore Diameter di

Enter 0 for solid shaft

Engagement Length lf

Friction Coefficient μ

Steel-steel: 0.10–0.15; Steel-cast iron: 0.12–0.15

Hub Elastic Modulus Ea

MPa

Shaft Elastic Modulus Ei

MPa

Hub Poisson's Ratio νa

Shaft Poisson's Ratio νi

Hub Yield Strength σsa

MPa

Shaft Yield Strength σsi

MPa

Power N

Overload Factor k

Speed n

RPM

Transmitted Torque T = 9550·k·N/n
- N·m

Min Contact Pressure Pfmin

- MPa

Hub Ratio qa = df/da

Shaft Ratio qi = di/df

Coefficient Ca

Coefficient Ci

Hub Min Deformation eamin

- mm

Shaft Min Deformation eimin

- mm

Min Effective Interference δemin
- mm

Hub Max Allowable Pressure Pfamax

- MPa

Shaft Max Allowable Pressure Pfimax

- MPa

Max Allowable Interference δmax
- mm

Design Check