ASTM A938 and ISO 7800 measure the simple torsional properties of metallic wire. These standard perform a single direction twist to failure on wire specimens that can span many different materials and geometries. These tests determines the number of rotations until failure as well as the peak torque.
ASTM A938 and ISO 7800 testing is typically performed by producers of raw materials, specifically manufacturers of metal. These wires can be used in a wide variety of end products such as mattress springs, instrument strings, and metal cabling. Torsion is often a resultant force experienced by the material under normal loading conditions, meaning the maximum torque is essential to evaluate the safety of the product.