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Hardness conversion calculator

Convert approximately between Rockwell C, Vickers and Brinell hardness, with an approximate tensile strength for carbon and low-alloy steel.

Approximate equivalents (carbon / low-alloy steel)45.0 HRC

446 HV · 421 HB · approximate tensile strength 1452 MPa (UTS ≈ 3.45 × HB)

Approximate conversions only, per ASTM E140 / ISO 18265 tables — typically ±2 HRC between scales and material-dependent. Never use as acceptance against a specification that names a specific test method; test by the specified method.

Formula

Conversions are interpolated from published approximate tables — there is no exact formula between scales. Approximate tensile strength UTS ≈ 3.45 × HB (MPa) for carbon and low-alloy steel.

Standard / source

ASTM E140 and ISO 18265 hardness conversion tables (empirical, material-specific). Values in this tool are approximations from those tables, not the tables themselves.

Worked example

45 HRC converts to approximately 446 HV and 421 HB, giving UTS ≈ 3.45 × 421 ≈ 1452 MPa.

Safety note

Approximate conversions only — typically ±2 HRC between scales and material-dependent. Never use a conversion as acceptance against a specification that names a specific test method; test by the specified method.