ASTM E 3246 : 2021

1.1This test method covers the determination of the Differential Indentation Depth hardness of metallic materials by the Differential Indentation Depth hardness principle. This standard provides the requirements for Differential Indentation Depth hardness testing machines and the procedures for performing Differential Indentation Depth hardness tests.

1.2This standard includes additional requirements in annexes:

1.3This standard includes non-mandatory information in appendixes which relates to the Differential Indentation Depth hardness test.

1.4Units—This standard specifies the units of force and length in the International System of Units (SI); that is, force in Newtons (N) and length in micrometers (µm). However, because of continued common usage, values are provided in other units of measure for information.

1.5The test principles, testing procedures, and verification procedures are essentially identical for all the Differential Indentation Depth hardness testing instruments. The testing instruments may use different test forces and indenter shapes. The type and size of the indenters are matched to the design of the instrument by the manufacturer. Accordingly, the indenters, probes and other instrument components are generally not interchangeable among manufacturers.

1.6The hardness number reported by these instruments are based on direct correlations to existing hardness scales as determined by each manufacturer for each instrument and hardness scale. Unless otherwise noted on the instrument or in the operating manual for the instrument, the hardness numbers reported by the instrument are only applicable to non-austenitic steels. See 5.6.1 for additional information.

1.7This 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.

1.8This 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.