This SAE Aerospace Recommended Practice (ARP) establishes flexure test procedures to determine and classify the fatigue strengths of reconnectable or permanent hydraulic tube joints. The procedure is intended for conducting flexure tests of fittings and joints for hydraulic tubing materials such as AMS 5561 (21Cr-6Ni-9Mn) steel or AMS 4944 (3AL-2.5V) titanium. A mean stress is applied by holding system pressure in the specimens and flexing in a rotary or planar bending test machine.