SAE ARP1321A

This recommended practice establishes a flexure test procedure for determining the fatigue strength of bent hydraulic tubing. The procedure is intended for conducting flexure fatigue testing of hydraulic and pneumatic tubing to determine the effects of tube fabrication methods, surface finishing, and other processing techniques on the fatigue performance of the tubing. A mean stress is applied by holding system pressure in the specimens and flexing in a rotary flexure test machine.