Hardness Conversion Calculator
Convert steel hardness between Rockwell C (HRC), Vickers (HV), and Brinell (HB), with an approximate tensile strength estimate, from the ASTM E140 and A370 tables, in your browser.
Converted hardness
-
About hardness conversion
Rockwell C, Vickers, and Brinell measure hardness differently, so cross-scale values come from a conversion table rather than a formula. This tool uses every whole-number HRC row (20–68) of the ASTM E140 Rockwell C table for Vickers and Brinell (10 mm carbide ball, 3000 kgf), and the ASTM A370 table for approximate tensile strength, interpolating between rows.
Conversions are approximate and apply to non-austenitic (carbon, alloy, ferritic and martensitic) steels. The standards give no Brinell value above 65 HRC and no tensile strength above 59 HRC, so those read “-”; Brinell values from 60 HRC up are outside the range recommended for Brinell testing.
What this does
This calculator converts steel hardness between Rockwell C (HRC), Vickers (HV), and Brinell (HB), and gives an approximate tensile strength estimate, from the ASTM E140 and ASTM A370 conversion tables.
How to use it
- Enter a hardness value and its scale.
- Read the equivalent values on the other scales.
- Note the approximate tensile strength.
- Treat results as estimates for steel.
How it works
Hardness scales are not related by a formula, so conversions come from the standard reference tables: ASTM E140 (Rockwell C to Vickers and Brinell) and ASTM A370 (approximate tensile strength). The tool holds every whole-number HRC row from 20 to 68 and interpolates between rows; values apply to non-austenitic steels.
Understanding your result
The converted hardness and tensile estimate come from standard reference tables, not an exact formula, and apply to non-austenitic steels (carbon, alloy, ferritic and martensitic). Treat cross-scale values as close approximations, and verify against the scale actually specified on your drawing when tolerances are tight.
Example
40 HRC is 392 HV and 371 HB, with an approximate tensile strength of 1,250 MPa (182 ksi). Above 59 HRC the tables give no tensile value, and above 65 HRC no Brinell value, so those read “-”.
Last updated .
Frequently asked questions
How are hardness scales converted?
They are not related by a formula, so conversions come from standard reference tables (ASTM E140 for Vickers and Brinell, ASTM A370 for tensile strength). This tool uses every whole-number HRC row and interpolates for values that fall in between.
How accurate are the conversions?
They are approximate and apply to non-austenitic steels (carbon, alloy, ferritic and martensitic), not austenitic stainless. Brinell and tensile estimates are not defined for very hard steel, so they may read “-” at the high end.
Is my data stored?
No. Everything is calculated locally in your browser.
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