Steel Hardness Conversion Calculator & Tables
Convert Vickers (HV), Brinell (HBW/HBS), Rockwell C (HRC), and Rockwell B (HRB) values for non-austenitic steels using separate hard- and soft-steel reference data.
Hardness Conversion Calculator
Enter a hardness value into one field. The other three fields will clear automatically if you change the input scale. Press Calculate to view approximate equivalent readings.
Approximate converted values
Approximate, table-based conversion with linear interpolation between adjacent entries. No extrapolation. N/A means that scale is not provided in the selected reference range. Do not use converted values in place of direct testing for certification or acceptance.
Hardness Conversion Reference Tables
There is no single universally valid HV–HB–HRC–HRB conversion curve. For steel, ASTM E140 separates the Rockwell C and Rockwell B reference ranges. The two tables below are shown independently rather than combined into misleading four-scale rows.
| Rockwell C (HRC) | Vickers (HV) | Brinell (HB) |
|---|---|---|
| 68 | 940 | — |
| 67 | 900 | — |
| 66 | 865 | — |
| 65 | 832 | 739 |
| 64 | 800 | 722 |
| 63 | 772 | 705 |
| 62 | 746 | 688 |
| 61 | 720 | 670 |
| 60 | 697 | 654 |
| 59 | 674 | 634 |
| 58 | 653 | 615 |
| 57 | 633 | 595 |
| 56 | 613 | 577 |
| 55 | 595 | 560 |
| 54 | 577 | 543 |
| 53 | 560 | 525 |
| 52 | 544 | 512 |
| 51 | 528 | 496 |
| 50 | 513 | 481 |
| 49 | 498 | 469 |
| 48 | 484 | 455 |
| 47 | 471 | 443 |
| 46 | 458 | 432 |
| 45 | 446 | 421 |
| 44 | 434 | 409 |
| 43 | 423 | 400 |
| 42 | 412 | 390 |
| 41 | 402 | 381 |
| 40 | 392 | 371 |
| 39 | 382 | 362 |
| 38 | 372 | 353 |
| 37 | 363 | 344 |
| 36 | 354 | 336 |
| 35 | 345 | 327 |
| 34 | 336 | 319 |
| 33 | 327 | 311 |
| 32 | 318 | 301 |
| 31 | 310 | 294 |
| 30 | 302 | 286 |
| 29 | 294 | 279 |
| 28 | 286 | 271 |
| 27 | 279 | 264 |
| 26 | 272 | 258 |
| 25 | 266 | 253 |
| 24 | 260 | 247 |
| 23 | 254 | 243 |
| 22 | 248 | 237 |
| 21 | 243 | 231 |
| 20 | 238 | 226 |
HRC reference range: 20–68. Brinell equivalents above about 55 HRC, where listed, are particularly approximate; no Brinell equivalents are shown above 65 HRC.
| Rockwell B (HRB) | Vickers (HV) | Brinell (HB) |
|---|---|---|
| 100 | 240 | 240 |
| 99 | 234 | 234 |
| 98 | 228 | 228 |
| 97 | 222 | 222 |
| 96 | 216 | 216 |
| 95 | 210 | 210 |
| 94 | 205 | 205 |
| 93 | 200 | 200 |
| 92 | 195 | 195 |
| 91 | 190 | 190 |
| 90 | 185 | 185 |
| 89 | 180 | 180 |
| 88 | 176 | 176 |
| 87 | 172 | 172 |
| 86 | 169 | 169 |
| 85 | 165 | 165 |
| 84 | 162 | 162 |
| 83 | 159 | 159 |
| 82 | 156 | 156 |
| 81 | 153 | 153 |
| 80 | 150 | 150 |
| 79 | 147 | 147 |
| 78 | 144 | 144 |
| 77 | 141 | 141 |
| 76 | 139 | 139 |
| 75 | 137 | 137 |
| 74 | 135 | 135 |
| 73 | 132 | 132 |
| 72 | 130 | 130 |
| 71 | 127 | 127 |
| 70 | 125 | 125 |
| 69 | 123 | 123 |
| 68 | 121 | 121 |
| 67 | 119 | 119 |
| 66 | 117 | 117 |
| 65 | 116 | 116 |
| 64 | 114 | 114 |
| 63 | 112 | 112 |
| 62 | 110 | 110 |
| 61 | 108 | 108 |
| 60 | 107 | 107 |
| 59 | 106 | 106 |
| 58 | 104 | 104 |
| 57 | 103 | 103 |
| 56 | 101 | 101 |
| 55 | 100 | 100 |
HRB reference range: 55–100. Values beyond 100 HRB are not offered. Rockwell B and C values are not forcibly mapped across the two reference tables.
How to Convert HRC, HRB, HB and HV
Hardness scales use different indenters, test loads and measurement methods. For steel, relationships are established empirically rather than through a universal exact formula. Select a reading such as 40 HRC, then convert using the Rockwell C reference range. The chart gives approximately 392 HV and 371 HB. For softer steel, 90 HRB corresponds to about 185 HV and 185 HB in the separate Rockwell B table.
For a value between listed points, this calculator uses straight-line interpolation within the selected table only. It does not extrapolate beyond the available data or treat a value in the wrong hardness scale as valid.
Machining Hardened Steel?
Hardness affects cutting tool selection, insert grade and machining parameters. Explore our CNC turning tools or contact OnMyToolings with your workpiece material and hardness.
Frequently Asked Questions
Is hardness conversion exact?
No. Hardness conversion is approximate because different hardness tests measure material behavior differently. Confirm specifications with a direct hardness test in the required scale.
Can I convert HRC 60 to HB?
In the hard-steel reference data, 60 HRC corresponds to approximately 654 HB and 697 HV. High-hardness Brinell equivalents are especially approximate and may not represent a practical Brinell measurement on the same part.
Why is the HRC or HRB result sometimes N/A?
Rockwell B and C are used over different hardness ranges, and ASTM E140 gives them separate tables. The tool does not invent a Rockwell C reading for soft-steel Table B or a Rockwell B reading for hard-steel Table A.
Can I use this chart for stainless steel, aluminum or titanium?
Not as a universal chart. Austenitic stainless steels and non-ferrous alloys require material-specific conversion data. These tables are for non-austenitic steels.
Can hardness reliably predict tensile strength?
No universally accurate relationship applies across all steel grades and heat treatments. The former single-table tensile-strength estimates were intentionally removed rather than implying a standard ASTM E140 tensile conversion.
References: ASTM E140 (scope and limitations); OMI Rockwell B reference data (60–100 HRB); AoboSteel supplementary values (55–59 HRB). Hard-steel HRC data are retained from the supplied original reference table, with invalid mixed-scale rows removed. Verify the applicable table and test conditions before specification use.
