Hardness Conversion Calculator

Convert between Brinell, Rockwell, and Vickers hardness scales

Hardness Scale Converter

Enter the hardness value you want to convert

Select the scale of your input value

Conversion Results

Brinell Hardness (HB)
303
kgf/mm²
Rockwell C (HRC)
32
dimensionless
Rockwell B (HRB)
107
dimensionless
Vickers Hardness (HV)
300
kgf/mm²
Hardness Category:
Medium
Carbon steels, alloys

Common Material Examples

Tool Steel (Heat Treated)

HV: 650 | HRC: 60 | HB: N/A
Very hard, cutting tools

Carbon Steel (Quenched)

HV: 300 | HRC: 32 | HRB: 107 | HB: 303
Medium hardness, structural parts

Mild Steel

HV: 127 | HRC: N/A | HRB: 72 | HB: 129
Soft, easily machined

Aluminum Alloy

HV: 80-150 | HRC: N/A | HRB: 35-75
Soft to medium, lightweight parts

Hardness Scales

Brinell Hardness (HB)
Unit: kgf/mm²
Spherical indenter, large loads
Rockwell C Scale (HRC)
Unit: dimensionless
Diamond cone, hard materials
Rockwell B Scale (HRB)
Unit: dimensionless
Steel ball, softer materials
Vickers Hardness (HV)
Unit: kgf/mm²
Diamond pyramid, universal scale

Hardness Categories

Very Hard600+ HV
Hard400-600 HV
Medium200-400 HV
Soft100-200 HV
Very Soft<100 HV

Testing Methods

Brinell: Steel ball indenter, large loads (187.5-3000 kgf)
Rockwell C: Diamond cone indenter, for hard materials
Rockwell B: Steel ball indenter, for softer materials
Vickers: Diamond pyramid, universal scale
Note: Conversions are approximate and based on empirical data for steel materials.

Understanding Hardness Scales

What is Material Hardness?

Hardness is a material's resistance to permanent deformation, particularly plastic deformation, indentation, or scratching. It's measured by pressing an indenter into the material under a specific load and measuring the resulting impression.

Why Different Scales?

  • Different Materials: Some scales work better for specific material types
  • Different Ranges: Each scale covers different hardness ranges effectively
  • Industry Standards: Different industries prefer different scales

Scale Characteristics

Brinell Hardness (HB)

Uses a hardened steel or carbide ball. Good for softer materials and provides good correlation with tensile strength.

Rockwell C (HRC)

Diamond cone indenter for hard materials like tool steels. Quick testing method with direct readout.

Rockwell B (HRB)

Steel ball indenter for softer materials. Alternative to Brinell for thinner specimens.

Vickers (HV)

Diamond pyramid indenter. Universal scale suitable for all materials from very soft to very hard.

Important Note on Conversions

Hardness conversions are approximate because different scales measure different material properties. The conversions in this calculator are based on empirical data for steel materials and may not be accurate for other alloys or materials. Always use the appropriate scale for your specific application when precision is critical.