The STS-50 torsion testing machine is designed to investigate torsional strength and to evaluate the resistance of materials to torsional loading, enabling determination of the shear strength of wire specimens. It is primarily intended for educational and teaching laboratories. The torsion test is a fundamental mechanical-properties test used in strength of materials laboratories to study the elastic-plastic behavior of wires under applied torque. In the STS-50, torque is applied manually through a gearbox mechanism, allowing smooth and controlled loading. The machine is equipped with a stiffness-compensation system to improve measurement accuracy. A digital torque indicator and an analog angle-of-twist indicator provide real-time measurement of the applied torque and specimen rotation.