Approximate tensile relation
Tensile strength often correlates with Brinell hardness for steels
Material property lookup
Hardness Conversion Table
Compare approximate hardness scale conversions for steel across Rockwell, Brinell, Vickers, and tensile strength estimates.
Instant hardness conversion lookup
Select a material or case
Select a hardness row to view approximate equivalent values across common scales.
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Reference table
Hardness conversion chart
| Reference | Group | Rockwell C HRC | Rockwell B HRB | Brinell HB | Vickers HV | Approx. Tensile Strength (MPa) |
|---|---|---|---|---|---|---|
| HRC 65 | Very hard steel | 65 | - | 739 | 832 | 2600 |
| HRC 60 | Hardened steel | 60 | - | 654 | 697 | 2300 |
| HRC 55 | Hardened steel | 55 | - | 560 | 595 | 2050 |
| HRC 50 | Hardened steel | 50 | - | 481 | 513 | 1750 |
| HRC 45 | Hardened steel | 45 | - | 421 | 448 | 1500 |
| HRC 40 | Hardened steel | 40 | - | 375 | 392 | 1300 |
| HRC 35 | Hardened steel | 35 | - | 331 | 345 | 1150 |
| HRC 30 | Medium hard steel | 30 | - | 286 | 302 | 980 |
| HRC 25 / HRB 101 | Medium hard steel | 25 | 101 | 255 | 266 | 850 |
| HRC 20 / HRB 96 | Medium hard steel | 20 | 96 | 225 | 238 | 760 |
| HRB 85 | Softer steel | - | 85 | 183 | 192 | 600 |
| HRB 75 | Softer steel | - | 75 | 156 | 164 | 500 |
Formulas
Hardness conversion notes
Test scales
Rockwell, Brinell, and Vickers use different indenters and loads
Hardness conversions are approximate. Material type, heat treatment, indentation load, surface condition, and standard can change equivalent values.
Reference
How engineers use hardness conversions
Specification checks
Hardness conversions help compare drawings, certificates, and supplier data reported on different scales.
Heat treatment
Hardness is commonly used to monitor hardening, tempering, and case-depth processes.
Wear resistance
Higher hardness often improves indentation and wear resistance, but may reduce toughness.
Limits
Use the required test scale for acceptance whenever a specification names one.
FAQ
Hardness conversion questions
Are hardness conversions exact?
No. Hardness conversions are approximate and depend on material behavior and test method.
Can hardness estimate tensile strength?
For many steels, hardness can provide a rough tensile strength estimate, but it should not replace tensile testing.
What is the difference between Rockwell and Brinell?
They use different test methods, indenters, loads, and measurement approaches.
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