TWI Industrial Member Report Summary 239/1984
K I Johnson, R M Rivett and S A Westgate
The various torsion test equipments recommended in recent years are described as is the historical development, application, and claimed advantages and disadvantages of the torsion test technique. Both manual and mechanical equipments have been developed and although the test was first proposed in the early 1950s, it has been little used except in France and Germany where test standards and procedures have been issued recently.
The torsion test has been evaluated at The Welding Institute (UK) and the Bundesanstalt für Materialprüfung (West Berlin), using both non-instrumented and instrumented manual techniques. Peel, chisel and cross-tension testing was also accomplished for purposes of comparison. Spot welds have been tested in 1.2 and 2.4mm thick low carbon steel and 0.9/1.0mm thick low carbon, rephosphorised and dual-phase steels. The torsion test gave an unreliable indication of weld size for welds in the 2.4mm low carbon steel and therefore is not recommended for general use. Plug failures occurred on peel, chisel and cross-tension testing full size welds in all the materials, but face failures generally occurred on torsion testing. There was no evidence to suggest that the torsion test gave results more sensitive to weld quality than the cross-tension test.