Hardness

How to use the converter

Select a measurement scale and enter a numeric value. The converter will instantly convert hardness into the three remaining scales: HRC (Rockwell C), HB (Brinell), HV (Vickers) and HRA (Rockwell A). Additionally, the machinability group and recommendations for choosing a tool are determined.

Which scale is used for what?

HRC (Rockwell C) is the most common scale for hardened and tempered steels. Used to control cutting tools, molds, bearings. Range 20–70 HRC.

HB (Brinell) - standard for forgings, castings, structural and normalized steels. Measured with a ball ⌀10 mm. Suitable for workpieces up to 450 HB. Often indicated on drawings and certificates.

HV (Vickers) - diamond pyramid 136°, universal scale from soft materials to hardened ones. Used for thin layers, nitrated surfaces, coatings. Numerically close to HB in the mid ranges.

HRA (Rockwell A) is a specialized scale for hard alloys (WC-Co), CBN, ceramics. Less common in mechanical engineering, but important when working with cutting ceramics.

Frequently Asked Questions

Why are the values ​​approximate? The converter uses ISO 18265 tables for alloy steel. Compliance depends on material composition and measurement method. Accuracy ±1–3 units in medium ranges.

What to do if the drawing indicates hardness in HB, and HRC is measured at the site? Enter the HB value - the converter will show the corresponding HRC. This is the most common use case.

Is it applicable to cast irons and non-ferrous metals? The ISO 18265 table is created for steels. For cast iron and aluminum, the correspondence is approximate - use as a guide, not for certification.

Regarding the selection of tools for a specific hardness, please contact our technologists.