public
Minimum shaft diameter as per AS1403 Table 2 Formula 2 for power applied and torque reversal conditions.
Minimum shaft diameter
$$ D_{min_{AS1403_{F2}}} = {\left({ 10 ^ 4 \cdot {F_S \over F_R} \cdot \sqrt{ \left({ K_S \cdot K \cdot \left({ M_q + {\left({ P_q \cdot D_{try} }\right) \over 8000} }\right) }\right) ^ 2 + {3 \over 4} \cdot T_q ^ 2 } }\right) ^ \left({ {1 \over 3} }\right)}
\; \; , {mm}
$$