This is a bench top educational machine for torsion test of small specimens.

It consists of two parallel members fixed together at both ends. At one end is a worm gear reducer where a torsion load is applied, and angular displacement measuring devices. At the other end is a torsion shaft with an arm attached to a load cell for measurement of torsion in both forward and reverse direction. This torsion shaft unit is slideable along the tubes to take up different length specimen. Both worm gear and torsion shaft have drive sockets for hexagonal head specimen. Round specimen requires special adapters. Torque is applied manually.

The equipment is designed such that torsion shaft angular displacement, or parallel tubes and loading arm deflections are negligible under maximum load. Angle of twist on the specimen is indicated by angular scales on the worm gear reducer shafts. A revolution counter is provided at the gear box to measure total input revolutions.

• Determination of modulus of rigidity and yield shear stress.
• Determination of modulus of rupture in torsion.
• Reversed torsion test to determine torsion hysteresis.