"Prob. $4\mathrm{.}6-16.$ The uniform aluminum$-$alloy shaft in Fig. P$4\mathrm{.}6-16$ is attached to a rigid wall at end A and is welded to a rigid flange at end $C.($a$)$ The holes in the flange were supposed to align with holes tapped in the wall plate, but actually an initial external torque $(T_B{)}_i$ must be applied in order to perfectly align the holes in the flange with the holes