Hardness tests press an indenter into a material and measure the dent, but each test uses a different indenter and load, so there is no exact formula between scales. Standard tables based on experiments are used instead; they are valid for steel and only approximately for other metals.
How to use the Hardness Conversion Calculator
- I have a hardness in
- Hardness value
Everything runs in your browser, so results appear instantly and nothing you type is sent to a server.
How it works
Your value is located between two rows of the steel conversion table and the other scales are linearly interpolated. Brinell values above 650 HB assume a tungsten-carbide ball.
Formula
Linear interpolation between rows of ASTM E140, Table 1Worked example
Inputs — I have a hardness in: Rockwell C (HRC); Hardness value: 45.
Results — Rockwell C (HRC) = 45.0; Vickers (HV) = 446; Brinell (HB) = 421; Approximate tensile strength = ≈ 215 ksi (1482 MPa).
Frequently asked questions
How hard is HRC 60?
About 697 HV, a typical hardened tool steel or knife blade.
Can I convert hardness for aluminium?
Not with this table; it is for steel. Other metals have their own tables.
Is tensile strength exact?
No; it is an approximation from hardness, typically within ±10% for carbon and alloy steels.
What formula does the Hardness Conversion Calculator use?
Linear interpolation between rows of ASTM E140, Table 1.