4.1 Significance—The data obtained from a compression test may include the yield strength, the yield point, Young’s modulus, the stress-strain curve, and the compressive strength (see Terminology E6). In the case of a material that does not fail in compression by a shattering fracture, compressive strength is a value that is dependent on total strain and specimen geometry.

4.2 Use—Compressive properties are of interest in the analyses of structures subject to compressive or bending loads or both and in the analyses of metal working and fabrication processes that involve large compressive deformation such as forging and rolling. For brittle or nonductile metals that fracture in tension at stresses below the yield strength, compression tests offer the possibility of extending the strain range of the stress-strain data. While the compression test is not complicated by necking as is the tension test for certain metallic materials, buckling and barreling can complicate results and should be minimized

This practice covers compression test in which the specimen is heated to a constant and uniform temperature and held at temperature while an axial force is applied at a controlled rate of strain. Machines used for compression testing shall conform to the requirements prescribed. The apparatus and method for heating the specimens are not specified. The procedure for temperature control, temperature measurement, strain rate during test, and strain measurement are presented in detail. The complete compression-test system consisting of jig, strain instrument, and recorders should be qualified, in accordance with the requirements prescribed.

1.1 This practice covers compression test in which the specimen is heated to a constant and uniform temperature and held at temperature while an axial force is applied at a controlled rate of strain.

1.2 In metals with extremely high proportional limit or low modulus of elasticity, 1.5 % total strain under load could be reached before the 0.2 %-offset yield strength is reached. In this event the end point of the test may be reported as the 0.2 percent-offset yield strength unless rupture occurs before that point.

1.3 For acceptable compression tests it is imperative that the specimens not buckle before the end point is reached. For this reason the equipment and procedures shall be designed to maintain uniform loading and axial alignment.

1.4 Preferred conditions of testing are recommended so that data from different sources conducting the tests will be comparable.

1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.