Spline Torque Capacity Calculator

Inputs

Pitch diameter (d)

Pitch or mean load radius diameter of the spline.

Number of teeth (z)

Number of spline teeth sharing the load before applying the load factor.

Effective tooth height (h)

Effective loaded flank height, not necessarily full tooth depth.

Engagement length (L)

Axial length over which the spline teeth carry load.

Allowable bearing pressure (p)

Allowable compressive pressure on the spline flanks.

MPa

Load distribution factor (K)

Fraction of the theoretical flank area assumed effective. Use less than 1 for misalignment and uneven tooth sharing.

Default result

Torque capacity(T)

450N·m

Also computed

Tangential force capacity(F_t)30,000N

30 kN · 6,744 lbf

Effective bearing area(A)375mm²

Method notes 3 notes

This is a flank bearing-pressure check: T = p_allow · z · h · L · K · d / 2.
Use a conservative load distribution factor when tooth contact, fit, lead error or shaft alignment are uncertain.
Final spline design should also check tooth-root shear/bending, shaft strength, hub hoop stress, fatigue and the applicable spline standard geometry.