Significance and Use 4.1 This test method provides a means for determining the modulus of rupture of a square cross section graphite specimen machined from the electrode core sample obtained according to Practice C783, with a minimum core diameter of 57 mm. This test method is recommended for quality control or quality assurance purposes, but should not be relied upon to compare materials of radically different particle sizes or orientational characteristics. For these reasons as well as those discussed in 4.2 an absolute value of flexural strength may not be obtained. 4.2 Specimen Size—The maximum particle size and maximum pore size vary greatly for manufactured graphite electrodes, generally increasing with electrode diameter. The test is on a rather short stubby beam, therefore the shear stress is not insignificant compared to the flexural stress, and the test results may not agree when a different ratio or specimen size is used.Scope 1.1 This test method covers determination of the modulus of rupture in bending of specimens cut from graphite electrodes using a simple square cross section beam in four-point loading at room temperature. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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.
