Hardness Conversion Chart
Technical Menu Posted on July 1st, 2015 by vapro* The following chart applies to plain carbon, low-alloy steels, cast steel and to a limited extent high-alloy and/or work hardened steel. *
| Brinell 3000kg Load 10mm Ball | Rockwell | Approximate Tensile Strength (PSI) | ||
|---|---|---|---|---|
| Diameter, mm | Hardness Number | B Scale | C Scale | |
| 2.85 | 461 | – | 48.5 | 242,000 |
| 2.90 | 444 | – | 47.1 | 230,000 |
| 2.95 | 429 | – | 45.7 | 219,000 |
| 3.00 | 415 | – | 44.5 | 212,000 |
| 3.05 | 401 | – | 43.1 | 202,000 |
| 3.10 | 388 | – | 41.8 | 193,000 |
| 3.15 | 375 | – | 40.4 | 184,000 |
| 3.20 | 363 | – | 39.1 | 177,000 |
| 3.25 | 352 | 110.0 | 37.9 | 170,000 |
| 3.30 | 341 | 109.0 | 36.6 | 163,000 |
| 3.35 | 331 | 108.5 | 35.5 | 158,000 |
| 3.40 | 321 | 108.0 | 34.3 | 152,000 |
| 3.45 | 311 | 107.5 | 33.1 | 147,000 |
| 3.50 | 302 | 107.0 | 32.1 | 143,000 |
| 3.55 | 293 | 106.0 | 30.9 | 139,000 |
| 3.60 | 285 | 105.5 | 29.9 | 136,000 |
| 3.65 | 277 | 104.5 | 28.8 | 131,000 |
| 3.70 | 269 | 104.0 | 27.6 | 128,000 |
| 3.75 | 262 | 103.0 | 26.6 | 125,000 |
| 3.80 | 255 | 102.0 | 25.4 | 121,000 |
| 3.85 | 248 | 101.0 | 24.2 | 118,000 |
| 3.90 | 241 | 100.0 | 22.8 | 114,000 |
| 3.95 | 235 | 99.0 | 21.7 | 111,000 |
| 4.00 | 229 | 98.2 | 20.5 | 109,000 |
| 4.05 | 223 | 97.3 | 18.8 | 104,000 |
| 4.10 | 217 | 96.4 | 17.5 | 103,000 |
| 4.15 | 212 | 95.5 | 16.0 | 100,000 |
| 4.20 | 207 | 94.6 | 15.2 | 99,000 |
| 4.25 | 201 | 93.8 | 13.8 | 97,000 |
| 4.30 | 197 | 92.8 | 12.7 | 94,000 |
| 4.35 | 192 | 91.9 | 11.5 | 92,000 |
| 4.40 | 187 | 90.7 | 10.0 | 90,000 |
| 4.45 | 183 | 90.0 | 9.0 | 89,000 |
| 4.50 | 179 | 89.0 | 8.0 | 88,000 |
| 4.55 | 174 | 87.8 | 6.4 | 86,000 |
| 4.60 | 170 | 86.8 | 5.4 | 84,000 |
| 4.65 | 167 | 86.0 | 4.4 | 83,000 |
| 4.70 | 163 | 85.0 | 3.3 | 82,000 |
| 4.80 | 156 | 82.9 | 0.9 | 80,000 |
| 4.90 | 149 | 80.8 | – | – |
| 5.00 | 143 | 78.7 | – | – |
| 5.10 | 137 | 76.4 | – | – |
| 5.20 | 131 | 74.0 | – | – |
| 5.30 | 126 | 72.0 | – | – |
| 5.40 | 121 | 69.8 | – | – |
| 5.50 | 116 | 67.6 | – | – |
| 5.60 | 111 | 65.7 | – | – |
