Metal Hardness Conversion Calculator
Convert applicable metallic hardness values between Brinell, Rockwell and Vickers scales. Shore scales are shown separately where applicable because Shore hardness is not directly interchangeable with metallic hardness.
Common hardness scales
For metallic materials, HBW, HRC, HRB and HV are commonly encountered hardness scales. The correct conversion depends on material and hardness range.
Conversion results
Hardness conversions are approximate correlations, not mathematical identities. For specification, certification or acceptance testing, use the hardness scale and test method required by the applicable material standard.
Shore hardness
Shore hardness is primarily used for elastomers, plastics and other softer materials. Shore A and Shore D readings should not be casually converted to Brinell, Rockwell or Vickers metallic hardness.
Shore A
Commonly used for softer rubber and elastomeric materials.
Shore D
Commonly used for harder plastics and harder elastomeric materials.
If the material is rubber, plastic or an elastomer, use the appropriate Shore scale rather than treating a metallic hardness conversion as equivalent.
How hardness conversion works
- Brinell: measures the size of an indentation made by a ball indenter.
- Rockwell: determines hardness from indentation depth under specified loads and indenter conditions.
- Vickers: uses a diamond pyramid indentation and measures its diagonals.
- Material dependence: conversion relationships differ between steels, nonferrous alloys and other materials.
- Range dependence: a conversion that works in one hardness range may not be appropriate outside that range.
- Test conditions: indenter geometry and test load are part of the hardness scale designation.
Example
Input: HBW 200
The calculator provides approximate equivalent values on supported Rockwell and Vickers scales.
Input: HRC 40
The calculator converts the value to approximate Brinell and Vickers equivalents within the applicable model range.
Use the displayed values as engineering estimates. When a material certificate specifies a hardness scale, report the actual measured scale rather than replacing it with a converted value.
Frequently Asked Questions
Can I convert Brinell to Rockwell?
Yes, approximate conversion is possible within suitable material and hardness ranges.
Can I convert Rockwell C to Vickers?
Yes. HRC-to-HV conversion is commonly used for approximate comparison of metallic hardness.
Can I convert Vickers to Brinell?
Yes. The calculator provides an approximate conversion where the selected range is appropriate.
Is HB the same as HBW?
HB is a general Brinell designation, while HBW specifically identifies the tungsten-carbide ball used in the test. Modern reporting commonly uses HBW with the test conditions.
Can Shore A be converted to HRC?
Not reliably as a general metallic hardness conversion. Shore A is intended primarily for soft elastomeric materials.
Are hardness conversions exact?
No. They are empirical correlations and can vary with material, heat treatment, microstructure and test range.
Which hardness scale should I use?
Use the scale specified by the material standard, drawing, customer requirement or applicable test procedure.
Can converted hardness be used for certification?
Normally, a converted value should not replace a required direct hardness measurement when certification or acceptance depends on the measured value.