ÖNORM EN ISO 8496

This International Standard specifies a method for a ring tensile test of tubes to reveal surface and internal defects by subjecting the test piece to strain until fracture occurs. This test may also be used to assess the ductility of tubes. The ring tensile test is applicable to tubes having an outside diameter exceeding 150 mm and a wall thickness no greater than 40 mm. The inside diameter shall be greater than 100 mm. 2 Principle Subjecting a ring cut from the end of a tube to strain in the circumferential direction until fracture occurs. 3 Apparatus 3.1 Two circular pins, of equal diameter with parallel axes, and movable in relation to each other while still remaining parallel. In principle, the diameter of the pins shall be the minimum permissible from strength considerations but, provided that the inside diameter of the tube allows, should be at least 3 times the wall thickness of the tube to be tested (see figure 1).