Use at your own risk. Verify inputs, assumptions and results independently before applying them.
Convert between Vickers, Brinell, Rockwell, Knoop, and Scleroscope hardness values using ASTM E140-97 curve-fit relationships.
Input definitions
- From scale
- Input hardness scale selected by the user. Unit: hardness scale.
- Hardness number
- Numeric hardness value measured on the selected input scale. Unit: selected hardness scale.
- To scale
- Target output scale: HV, HB, or HRC. Unit: hardness scale.
Worked example
Select input scale HV, enter 560, and choose output HB: the displayed estimate is 527 HB. Choosing HRC instead gives 53 HRC. These curve-fit conversions are intended for the stated non-austenitic-steel scope and are approximate. They do not replace a hardness test on the target scale, and must not be generalized to another material family or used outside the supported range.
Method notes
Read more here.
- Standard hardness conversion for metals according to ASTM E 140-97, September 1999, conversion for non-austenitic steels, Table 1. The accuracy of the conversion depends on the accuracy of the provided data and the resulting curve fits.
- Indentation hardness is not a single fundamental property but a combination of properties, and varies with the type of test. The modulus of elasticity and the depth of indentation influence conversions. Therefore separate conversion tables are necessary for different materials.
- Brinell hardness numbers in parentheses are outside the range where HB is greater than 630. This limit is set to avoid errors introduced by deformation of the ball indenter itself.
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