Materials

Hardness Converter

Convert hardness values between Rockwell, Brinell, Vickers, and other scales.

Input Parameters

Input Scale

Hardness Value

Results

Enter a hardness value and click Convert

What is Hardness?

Hardness is a material's resistance to localized plastic deformation, typically from indentation. It's a critical property for selecting materials for wear resistance, machinability, and load-bearing applications.

Different hardness scales use different indenters and loads, making direct comparison impossible without conversion. This tool converts between the most common industrial scales based on ASTM E140 standards.

How to Use

Select the hardness scale of your known value
Enter the hardness value within the valid range
Click Convert to see equivalent values
The input scale is highlighted in the results

FAQs

Each hardness scale has a valid range. When a hardness value falls outside a scale's measurable range, it cannot be converted. For example, HRB is only valid up to about 100, which corresponds to roughly 20 HRC. Very hard materials can only be measured on HRC, HV, or specialized scales.

HRC (Rockwell C) is standard for hardened steels and tool steels. HRB (Rockwell B) is used for softer materials like mild steel, brass, and aluminum. Vickers (HV) works across the widest range and is preferred for research. Brinell (HB) is best for castings and materials with coarse grain structure.

These conversions are based on ASTM E140 standards for steel. Non-ferrous metals (aluminum, copper, brass) and other materials have different conversion relationships. For non-steel materials, use material-specific conversion tables or direct testing.

Material hardness directly affects tool selection, cutting speeds, and feeds. Harder materials require slower speeds, stronger tool grades, and often carbide or ceramic inserts. Knowing the hardness helps predict tool wear and optimize machining parameters.

The tensile strength shown is an approximation using the common formula (UTS ≈ HV × 3.45 MPa). Actual tensile strength varies based on material composition, heat treatment, and microstructure. Use this as a rough estimate only - proper tensile testing is required for engineering specifications.

Limitations

• Conversions are based on ASTM E140 for steel only
• Non-ferrous metals require different conversion tables
• Values outside scale ranges cannot be converted
• Tensile strength estimate is approximate only
• For critical specifications, perform direct testing