Guest's theory

Rankine's theory

St Venant's theory

VonMises theory

jam nut

castle nut

sawn nut

ring nut

the strength of the shaft

the rigidity of the shaft

both the strength and rigidity of the shaft

the ductility of the shaft

Correct

Incorrect

Torque in each shaft is the same

Shear stress in each shaft is the same

Angle of twist of each shaft is the same

Torsional stiffness of each shaft is the same