Hardest Engineering Materials

These are the hardest materials in our library, ranked by the hardness they can reach. Medium-carbon and alloy steels lead once heat treated.

Material Hardness (typical max)
1045 Steel 55 HRC (hardened)
4340 Steel 54 HRC (heat treated)
4140 Steel 50 HRC (heat treated)
17-4 PH Stainless 44 HRC
Titanium Grade 5 36 HRC
Gray Cast Iron About 95 HRB
304 Stainless About 80 HRB (annealed)

Hardness depends heavily on heat treatment. The steels above are soft in the annealed state and only reach these values after hardening and tempering.

Hardness comes from heat treatment. Most of the hardness in steel is developed by quenching and tempering. Specify the required hardness, not just the alloy, when wear resistance matters.

See the Hardness Conversion Chart and the Hardness Conversion Calculator.

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The calculators and tools on Formula Factory are provided for general guidance and informational purposes only. Results are estimates based on standard formulas and the values you enter — they do not constitute professional engineering, electrical, or architectural advice. Always verify calculations with a qualified professional before making decisions for any safety-critical, code-compliance, or commercial application. Formula Factory makes no representations or warranties as to the accuracy or completeness of any result, and accepts no liability for errors, omissions, or any outcomes arising from reliance on this information.