Hardness Conversion Calculator
Convert steel hardness between Rockwell C (HRC), Vickers (HV), and Brinell (HB), with an approximate tensile strength estimate. Interpolated per ASTM E140 / SAE J417, 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 interpolates between the standard reference points (per ASTM E140 / SAE J417) and estimates approximate tensile strength.
Conversions are approximate and apply to carbon and low-alloy steels. Brinell and tensile estimates are not defined for very hard steel, so they may show as “-” at the high end.
What this does
This calculator converts steel hardness between Rockwell C (HRC), Vickers (HV), and Brinell (HB), and gives an approximate tensile strength estimate, interpolated from ASTM E140 / SAE J417.
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 table (ASTM E140 / SAE J417). The tool interpolates between published anchor points; values apply to carbon and low-alloy steels.
Understanding your result
The converted hardness and tensile estimate come from standard reference tables, not an exact formula, and apply to carbon and low-alloy steels. 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 roughly 392 HV and about 375 HB. Brinell and tensile estimates may read “-” for very hard steel.
Sources & methodology
Last updated .
Frequently asked questions
How are hardness scales converted?
They are not related by a formula, so conversions come from a standard reference table (ASTM E140 / SAE J417). This tool interpolates between the published anchor points for values that fall in between.
How accurate are the conversions?
They are approximate and apply to carbon and low-alloy steels. 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.
Related tools
Inch to MM Converter
Convert between inches and millimeters using the exact 25.4 mm definition. Works both directions, entirely in your browser.
Decimal to Fraction Converter
Convert a decimal inch to the nearest machinist fraction (1/8 down to 1/128), reduced to lowest terms, with the exact-vs-approximate difference shown. Runs in your browser.
SFM to RPM Calculator
Convert cutting speed (SFM or SMM) to spindle RPM for a given tool diameter, or read the cutting speed from an RPM. Inch and metric, in your browser.
Feed Rate Calculator
Calculate machine feed rate (IPM or mm/min) from spindle RPM, number of teeth, and chip load, plus the feed per revolution. Inch and metric, in your browser.