Diagram shows an aluminum shaft A B with a support at A, marked 1 of length 4,000 millimeters and a brass shaft B C with a support at C, marked 2 of length 3,000 millimeters with a flange in between at B. The shafts are centered on the x axis. A torque T is applied at B.

Having determined τ1 and τ2, the internal torques carried by each shaft can be computed.

For shaft (2):

T2=τ2J2c2

   =(-50 N/mm2)(4,021,239 mm4)40 mm   =-5,026,549 N-mm   =-5,026.549 N-m