Tensile Strength from Hardness Calculator — HV, HBW, and HRC to UTS

Hardness testing is the fastest and most economical mechanical test in metallurgy. Because hardness and tensile strength both reflect resistance to plastic deformation, a well-established empirical relationship allows tensile strength to be estimated from hardness — avoiding destructive tensile testing for initial assessment, quality control checks, and fitness-for-service evaluations. This calculator provides UTS estimates from Vickers (HV), Brinell (HBW), and Rockwell C (HRC) using ASTM, ISO, and BS correlations.

UTS vs Hardness Correlation Chart — Carbon and Low-Alloy Steels

When Not to Use Hardness-UTS Correlations

• Design-critical applications: Always specify actual tensile testing per ASTM A370 or ISO 6892-1 for structural components, pressure vessels, and safety-critical parts.
• Cold-worked or work-hardened materials: Work hardening increases hardness more than proportionally relative to UTS; correlations overestimate strength.
• Cast irons: Graphite morphology (flake vs nodular vs compacted) affects the hardness-strength relationship fundamentally — separate correlations are required for each type.
• Non-ferrous alloys: Aluminium, copper, titanium, and nickel alloys have different hardness-strength relationships — use alloy-specific data sheets.

References

• ASTM E140-12b Standard Hardness Conversion Tables for Metals.
• ISO 18265:2013 Metallic materials — Conversion of hardness values.
• Tabor, D., The Hardness of Metals. Oxford University Press, 1951 (reprinted 2000).

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