Hardness Conversion Chart
| C | A | D | 15N | 30N | 45N | Vickers | Knoop | Brinell |
| 150kgt | 60kgt | 100kgt | 15kgt | 30kgt | 45kgt | Hardness | Hardness | Hardness |
| diamond | diamond | diamond | diamond | diamond | diamond | 500gr | 3000kgt | |
| and over | 10mm ball | |||||||
| 68 | 85.6 | 76.9 | 93.2 | 84.4 | 75.4 | 940 | 920 | |
| 67 | 85.0 | 76.1 | 92.9 | 83.6 | 74.2 | 900 | 895 | |
| 66 | 84.5 | 75.4 | 92.5 | 82.8 | 73.3 | 865 | 870 | |
| 65 | 83.9 | 74.5 | 92.2 | 81.9 | 72.0 | 832 | 846 | (739) |
| 64 | 83.4 | 73.8 | 91.8 | 81.1 | 71.0 | 800 | 822 | (722) |
| 63 | 82.8 | 73.0 | 91.4 | 80.1 | 69.9 | 772 | 799 | (705) |
| 62 | 82.3 | 72.2 | 91.1 | 79.3 | 68.8 | 745 | 776 | (688) |
| 61 | 81.8 | 71.5 | 90.7 | 78.4 | 67.7 | 720 | 754 | (670) |
| 60 | 81.2 | 70.7 | 90.02 | 77.5 | 66.6 | 697 | 732 | (654) |
| 59 | 80.7 | 69.9 | 89.8 | 76.6 | 65.5 | 674 | 710 | (634) |
| 58 | 80.1 | 69.2 | 89.3 | 75.7 | 64.3 | 653 | 690 | 615 |
| 57 | 79.6 | 68.5 | 88.9 | 74.8 | 63.2 | 633 | 670 | 595 |
| 56 | 79.0 | 67.7 | 88.3 | 73.9 | 62.0 | 613 | 650 | 577 |
| 55 | 78.5 | 66.9 | 87.9 | 73.0 | 60.9 | 595 | 630 | 560 |
| 54 | 78.0 | 66.1 | 87.4 | 72.0 | 59.8 | 577 | 612 | 543 |
| 53 | 77.4 | 65.4 | 86.9 | 71.2 | 58.6 | 560 | 594 | 525 |
| 52 | 76.8 | 64.6 | 84.4 | 70.2 | 57.4 | 544 | 576 | 512 |
| 51 | 76.3 | 63.8 | 85.9 | 69.4 | 56.1 | 528 | 558 | 496 |
| 50 | 75.9 | 63.1 | 85.5 | 68.5 | 55.0 | 513 | 542 | 481 |
| 49 | 75.2 | 62.1 | 85.0 | 67.6 | 53.8 | 498 | 526 | 469 |
| 48 | 74.7 | 61.4 | 84.6 | 66.7 | 52.5 | 484 | 510 | 455 |
| 47 | 74.1 | 60.8 | 83.9 | 65.8 | 51.4 | 471 | 495 | 443 |
| 46 | 73.6 | 60 | 83.5 | 64.8 | 50.3 | 458 | 480 | 432 |
| 45 | 73.1 | 59.2 | 83.0 | 64.0 | 49.0 | 446 | 466 | 421 |
| 44 | 72.5 | 58.5 | 82.5 | 63.1 | 47.8 | 434 | 452 | 409 |
| 43 | 72.0 | 57.7 | 82.0 | 62.2 | 46.7 | 423 | 438 | 400 |
| 42 | 71.5 | 56.9 | 81.5 | 61.3 | 45.5 | 412 | 426 | 390 |
| 41 | 70.9 | 56.2 | 80.9 | 60.4 | 44.3 | 402 | 414 | 381 |
| 40 | 70.4 | 55.4 | 80.4 | 59.5 | 43.1 | 392 | 402 | 371 |
| 39 | 69.9 | 54.6 | 79.9 | 58.6 | 41.9 | 382 | 391 | 362 |
| 38 | 69.4 | 53.8 | 79.4 | 57.7 | 40.8 | 372 | 380 | 353 |
| 37 | 58.9 | 53.1 | 78.8 | 56.8 | 39.6 | 363 | 370 | 344 |
| 36 | 68.4 | 52.3 | 78.3 | 55.9 | 38.4 | 354 | 360 | 336 |
| 35 | 67.9 | 51.5 | 77.7 | 55.0 | 37.2 | 345 | 351 | 327 |
| 34 | 67.4 | 50.8 | 77.2 | 54.2 | 36.1 | 336 | 342 | 319 |
| 33 | 66.8 | 50.0 | 76.6 | 53.3 | 34.9 | 327 | 334 | 311 |
| 32 | 66.3 | 49.2 | 76.1 | 52.1 | 33.7 | 318 | 326 | 301 |
| 31 | 65.8 | 48.4 | 75.6 | 51.3 | 32.5 | 310 | 318 | 294 |
| 30 | 65.3 | 47.7 | 75.0 | 50.4 | 31.3 | 302 | 311 | 286 |
| 29 | 64.8 | 47.0 | 74.5 | 49.5 | 30.1 | 294 | 304 | 279 |
| 28 | 64.3 | 46.1 | 73.9 | 48.6 | 28.9 | 286 | 297 | 271 |
| 27 | 63.8 | 45.2 | 73.3 | 47.7 | 27.8 | 279 | 290 | 264 |
| 26 | 63.3 | 44.6 | 72.8 | 46.8 | 26.7 | 272 | 284 | 258 |
| 25 | 62.8 | 43.8 | 72.2 | 45.9 | 25.5 | 266 | 278 | 253 |
| 24 | 62.4 | 43.1 | 71.6 | 45.0 | 24.3 | 260 | 272 | 247 |
| 23 | 62.0 | 42.1 | 71.0 | 44.0 | 23.1 | 254 | 266 | 243 |
| 22 | 61.5 | 41.6 | 70.5 | 43.2 | 22.0 | 248 | 261 | 237 |
| 21 | 61.0 | 40.9 | 69.9 | 42.3 | 20.7 | 243 | 256 | 231 |
| 20 | 60.5 | 40.1 | 69.4 | 41.5 | 19.6 | 238 | 251 | 226 |
