4.1 This test method is used to measure the strength of sintered, including post-treated, specimens. Transverse rupture strength is not a design value. For many sintered materials, transverse rupture strength is approximately twice the ultimate tensile strength.
1.1 This test method covers determination of the transverse rupture strength of sintered, including post-treated, powder metallurgy test specimens by subjecting them to a uniformly increasing transverse force under controlled conditions. The term “transverse rupture strength” as used herein, defines the stress, calculated from the flexure formula required to break a specimen as a simple beam supported near the ends and applying the force midway between the fixed line center of the supports.
1.2 Limitations—The transverse rupture test is only applicable to relatively brittle materials. In cases where a ductile specimen is being tested and the permanent deflection as a result of testing exceeds 0.020 in. (0.50 mm), the test results may be questionable.
1.3 Test Method B406 should be consulted for determining the transverse rupture strength of cemented carbides.