Since the rotation angle at $\mathrm{B}$ is known (i.e., ${\mathrm{\varphi }}_{\mathrm{B}}=3^{\circ }$), the above relations can be combined with the torque-twist relationships...

${\mathrm{\varphi }}_1=\frac{{\mathrm{T}}_1{\mathrm{L}}_1}{{\mathrm{J}}_1{\mathrm{G}}_1} \mathrm{and} {\mathrm{\varphi }}_2=\frac{{\mathrm{T}}_2{\mathrm{L}}_2}{{\mathrm{J}}_2{\mathrm{G}}_2}$

...to compute the internal torques ${\mathrm{T}}_1$ and ${\mathrm{T}}_2$ in the stainless steel and bronze shafts. Once these internal torques are known, the torque $\mathrm{T}$ can be computed from equilibrium and the shear stress in each shaft can be calculated with the torsion formula.