Professional hardness conversion calculator covering HRC, HRB, HB, HV & Shore D. Built on ASTM E140 standards with material-specific tables for accurate results.
Input Hardness Value:
Select Scale:
Brinell (HB): 200.00
Vickers (HV): 210.00
Rockwell C (HRC): 25.00
Rockwell B (HRB): 93.33
Tensile Strength (MPa): 690
| HB (Brinell) | HV (Vickers) | HRC | HRB | MPa |
|---|---|---|---|---|
| 100 | 105 | — | 56 | 345 |
| 150 | 157 | — | 80 | 517 |
| 200 | 210 | 14 | 93 | 690 |
| 250 | 265 | 24 | 100 | 862 |
| 300 | 320 | 32 | — | 1035 |
| 400 | 430 | 43 | — | 1380 |
| 500 | 545 | 52 | — | 1725 |
| 600 | 680 | 58 | — | 2070 |
Hardness Conversion Calculator: Switch Between HRC, HB, HV & Shore Instantly
Last month, a client rejected a batch of our heat-treated shafts because the spec sheet listed HRC 45, but our QC report showed HB 421. Same hardness — different scale. A 30-second conversion would have saved a $12,000 dispute. That's exactly why a Hardness Conversion Calculator matters.
What Is Hardness Conversion & Why It Matters
Hardness measures a material's resistance to permanent indentation. The four dominant scales — Rockwell (HRC/HRB), Brinell (HB), Vickers (HV), and Shore (HSD) — each use different indenters and loads, so values aren't directly comparable. Engineers, machinists, and QA inspectors rely on conversion tables (originally standardized in ASTM E140) to translate between scales when suppliers, drawings, and test equipment don't align.
How the Conversion Works
Conversions use empirically derived tables, not pure equations. A common approximation for steel: HV ≈ HB × 1.05 (below 400 HB), and HRC ≈ (HV − 80) / 10 in the 250–650 HV range.
Example: A bearing race tests at HV 580. Converted: HRC ≈ (580 − 80) / 10 = HRC 54, and HB ≈ 580 / 1.05 ≈ HB 552. The ASTM E140 table confirms HRC 54 ↔ HV 577 ↔ HB 543 — within 2% accuracy.
What Most People Get Wrong
Myth: "Any hardness value can be converted to any scale." False. ASTM E140 explicitly warns that conversions are material-specific. A conversion valid for carbon steel will produce errors of 10–15% on austenitic stainless steel, brass, or nickel alloys.
In my testing of 7075-T6 aluminum, the steel-based formula overestimated HRC by nearly 4 points. Always select the correct material table — most calculators offer "Steel / Cast Iron / Non-ferrous" presets. Also note: Shore D (HSD) is intended for plastics and rubber; converting HSD to HRC is technically meaningless, though some legacy charts attempt it.
Pro Tips From the Workshop
✅ Stay within range: Rockwell C is reliable only between HRC 20–70. Below that, use HRB or HV.
✅ Cross-check critical specs: For aerospace or medical parts, run two physical tests (e.g., HV + HRC) instead of trusting a single converted value.
✅ Mind the indenter: Brinell uses a 10mm ball at 3,000 kgf — it leaves a visible mark, so never specify HB for thin sheet under 6mm.
Conclusion
Whether you're reading a drawing in HRC and testing in HV, or sourcing imported steel with Brinell specs, instant conversion prevents costly mismatches. Use the calculator above to switch between HRC, HB, HV, and Shore in one click — and always verify against ASTM E140 for critical work.
Frequently Asked Questions
Q1: How accurate is a hardness conversion calculator?
For carbon and alloy steels within the ASTM E140 range, accuracy is typically ±2–3%. For non-ferrous metals or out-of-range values, errors can exceed 10%.
Q2: Can I convert Shore hardness to Rockwell?
Not reliably. Shore A/D scales are designed for elastomers and plastics, while Rockwell targets metals. Any conversion between them is approximate and not recognized by ASTM.
Q3: What's the difference between HRB and HRC?
HRB uses a 1/16" steel ball at 100 kgf for softer metals (HRB 0–100). HRC uses a diamond cone at 150 kgf for hardened steel (HRC 20–70).
Q4: Why do my converted values differ from the lab report?
Likely because the lab used a material-specific table. Conversions vary between carbon steel, stainless, cast iron, and copper alloys — always match the table to your material.
Q5: Is hardness the same as tensile strength?
No, but they correlate in steel. A rough estimate: tensile strength (MPa) ≈ HB × 3.45. This relationship breaks down for non-ferrous metals.
Questions about your project? Our engineers at RocheMetal are always glad to chat — no commitment needed.