Provides Rockwell hardness test procedures for metallic materials, including equipment verification, indentation procedures, and conversion guidance used in North American specifications and supplier quality systems.

ASTM

ASTM E18

Revision: 2022

Material testing

Standard test methods for Rockwell hardness of metallic materials

Provides Rockwell hardness test procedures for metallic materials, including equipment verification, indentation procedures, and conversion guidance used in North American specifications and supplier quality systems.

Test method

Uses preliminary and total force sequences with diamond conical or ball indenters on regular and superficial scales; hardness is derived from depth difference measurements after defined force cycles.

Specimen requirements

Specimens shall be thick enough to prevent bulging or marking on the opposite surface. Surfaces must be smooth and free of features that disturb indentation depth measurement; support must be rigid.

ASTM E18 is frequently referenced alongside ISO 6508 for global supply chains serving ASTM-oriented customers.