ASTM E18

Full Name

ASTM E18 – Standard Test Methods for Rockwell Hardness of Metallic Materials

Scope

ASTM E18 is a standard test method used to determine the Rockwell hardness of metallic materials. Rockwell hardness is a measure of a material’s resistance to indentation, similar to Brinell hardness. However, the Rockwell test uses a diamond indenter or a hardened steel ball and a different measurement method.

Test procedure:

  • Sample preparation: ensure the test surface is smooth and free of defects.
  • Initial indentation: apply a minor load to the indenter, typically 10 kgf or 60 kgf, to establish a reference point.
  • Major load: apply a major load to the indenter, typically 60 kgf, 100 kgf, or 150 kgf, depending on the expected hardness of the material.
  • Measurement: measure the depth of the total indentation, which is the difference between the initial and final depths.
  • Calculation: Rockwell hardness is expressed as a number based on the depth of the indentation. The scale used depends on the indenter and load combination.

Common Rockwell scales:

  • HRC: diamond indenter with 60 kgf major load (hard materials)
  • HRB: steel ball indenter with 100 kgf major load (softer materials)
  • HRC and HRB: diamond indenter with 150 kgf major load (intermediate hardness)
  • HRF: steel ball indenter with 60 kgf major load (very soft materials)

ASTM E18 Accredited Laboratory

Applied Testing & Geosciences, LLC is accredited for performing tests using the ASTM E18 standard.

Contact us today to learn more about our testing capabilities and how we can support your business.

Resources

Keywords

Rockwell hardness; metallic materials; test method; indentation; diamond indenter; steel ball; load; measurement; calculation; HRC; HRB; HRC and HRB; HRF; quality control; material selection; process monitoring; research and development; manufacturing; construction; inspection; structural components; materials; surface preparation; defects; strain hardening; grain size; heat treatment; material composition; factors affecting Rockwell hardness; applications; testing services; ASTM E18

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