This standard specifies the test method for the torsion performance of bare wires (including conductors with round and special-shaped cross-sections). It is applicable to the evaluation of the ability to withstand plastic deformation by subjecting a specimen of specified length to unidirectional torsion about its own axis until fracture or a specified number of twists is reached. The standard details the test equipment, specimen preparation, specific procedures, and result evaluation. Implementation of this method must be used in conjunction with Part 1, "General Principles," of the same series of standards. The test generally requires the use of a specialized wire torsion testing machine.