What is Vickers to Rockwell Hardness Converter in metallurgy?

Vickers to Rockwell Hardness Converter is an important concept in materials science and engineering metallurgy that influences the selection, processing, and performance of metallic materials in industrial applications. Understanding this topic enables engineers to make informed decisions about material selection, heat treatment, fabrication, and inspection.

How does this relate to real engineering applications?

This metallurgical principle is directly applied in structural engineering, pressure vessel fabrication, aerospace manufacturing, oil and gas production, and automotive design. Engineers reference standard handbooks (ASM Handbook series), international codes (ASME, EN ISO, ASTM), and material certificates to specify and verify compliance with metallurgical requirements throughout the design and fabrication process.

Where can I learn more about this topic?

Key reference texts include: ASM Handbook series (Vols 1, 4, 9, 11); Steels: Microstructure and Properties by Bhadeshia and Honeycombe; Materials Science and Engineering by Callister and Rethwisch. Professional bodies including ASM International, TWI, and IOM3 also provide technical training and certification programmes for metallurgical engineers.

Vickers to Rockwell Converter (HV ↔ HRC)

The Vickers hardness test (HV) and Rockwell C hardness test (HRC) are the two most widely used hardness measurement methods in engineering. Converting between them is essential for comparing specifications written in different scales — for example, when a material spec calls for HRC 58–62 but your laboratory only has a Vickers tester, or when a weld spec limits HAZ hardness to 350 HV but the drawing specifies the component hardness in HRC. This dedicated HV ↔ HRC converter uses ASTM E140-12b tabulated data with polynomial curve fitting for accurate interpolation.

Vickers ↔ Rockwell C Hardness Converter

Conversion Direction

Input Value

Converted hardness—

Also in Brinell (HBW)—

Approx. UTS for steel (MPa)—

Typical steel condition at this hardness—

Conversion per ASTM E140-12b Standard Hardness Conversion Tables for Metals.
Valid for wrought carbon and alloy steels only. Not applicable to cast iron, non-ferrous alloys, case-hardened surfaces (use microhardness for case depth profiles), or coatings.
Accuracy: ±1–2 HRC or ±10–20 HV for most steel types within the applicable range.

Figure: Hardness scale comparison — HRC, Vickers HV, Brinell HBW and approximate UTS for carbon and alloy steels per ASTM E140-12b. © metallurgyzone.com/

ASTM E140 Hardness Conversion Quick Reference

HRC	HV	HBW	Approx. UTS (MPa)	Typical Application
68	940	895	3,090	Maximum for steel; file-hard
62	746	710	2,450	As-quenched high-carbon steel
58	633	603	2,080	Case-hardened surface, bearing steel
52	512	488	1,680	Hardened H13 tool steel (tempered)
45	432	411	1,420	Austempered ductile iron (ADI)
40	381	363	1,250	Q&T S690 structural steel
35	336	320	1,100	Bainitic steels; hardened spring steel
30	294	280	966	NACE MR0175 max HAZ limit
25	260	248	856	Normalised 4140; annealed tool steel
20	238	227	783	Lower limit of HRC; above = use HRB

Important Conversion Limitations

Material-specific: ASTM E140 tables apply only to wrought carbon and low-alloy steels. Conversion for cast iron, non-ferrous alloys, stainless steels, and nickel alloys requires alloy-specific tables and will give inaccurate results if the standard tables are used.
Surface condition: For case-hardened components, HRC measures the through-thickness average of a deep indent (1.5mm penetration) — not the surface case hardness. Use Vickers microhardness (HV0.1–HV1) for case hardness and depth profiling.
Temperature: Hardness conversions are calibrated at room temperature (23°C ± 5°C). Elevated-temperature hardness testing uses specialised instruments and separate conversion data.

References

ASTM E140-12b Standard Hardness Conversion Tables for Metals Relationship Among Brinell, Vickers, Rockwell, Superficial, Knoop, Scleroscope, and Leeb Hardness.
ISO 18265:2013 Metallic materials — Conversion of hardness values.

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