4.1 The compressive strength or crush-extrusion resistance of a gasket material is a major factor with regard to the selection of a given material for use in a particular sealing application. The significance of the test method is based, in part, on the assumption that a material, once it has been crushed or extruded, will no longer function as effectively as a seal. This assumption can only be used as a guide, however, since exact yield or failure points are difficult to define for gasket materials (which are usually viscoelastic in nature). Two or more materials can be compared to determine differences in their resistance to compressive stress. A sample of material can be compared to an established standard or previously determined characteristics on original lots of the same material, for quality assurance purposes. See 6.2 for discussion of specimen area and geometry effects.

1.1 This test method covers the determination of compressive strength characteristics (crush-extrusion resistance) of gasket materials at elevated temperature.

1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.

1.3 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.

1.4 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.