Ring-Expanding Test to ISO 8495, DIN 50137, ASTM A370
The ring-expanding test to ISO 8495, DIN 50137 and ASTM A370 is used to assess the ability of tubes to undergo plastic deformation and to reveal production defects on the outer surface of the tube and within the tube wall. Defects can be detected based on the appearance of the fracture.
For a ring-expanding test, a ring cut from the end of a tube is expanded using a conical mandrel until fracture occurs. Identical specimens can be stacked on top of each other when performing the test (see sketch). The conical mandrel is pressed into the rings, until the expansion reaches the specified value.
The test is considered passed if no cracks are detected in the tube after the test.
The ring-expanding test is performed on tubes having an outside diameter from 18-150 mm and a wall thickness from 2-16 mm.
