| Rockwell
C Scale, 150-kgf Load, Diamond Penetrator |
Vickers Hardness Number |
Brinell Hardness, 3000-kgf Load, 10-mm Ball |
Knoop Hardness, 500-gf Load and Over |
Rockwell A Scale, 60-kgf Load, Diamond Penetrator |
Rockwell Superficial Hardness | |||
| 15N
Scale, 15-kgf Load, Diamond Penetrator |
30N Scale 30-kgf Load, Diamond Penetrator |
45N Scale, 45-kgf Load, Diamond Penetrator |
Approximate Tensile Strength, ksi (MPa) |
|||||
| 68 | 940 | --- | 920 | 85.6 | 93.2 | 84.4 | 75.4 | --- |
| 67 | 900 | --- | 895 | 85.0 | 92.9 | 83.6 | 74.2 | --- |
| 66 | 865 | --- | 870 | 84.5 | 92.5 | 82.8 | 73.3 | --- |
| 65 | 832 | 739 | 846 | 83.9 | 92.2 | 81.9 | 72.0 | --- |
| 64 | 800 | 722 | 822 | 83.4 | 91.8 | 81.1 | 71.0 | --- |
| 63 | 772 | 706 | 799 | 82.8 | 91.4 | 80.1 | 69.9 | --- |
| 62 | 746 | 688 | 776 | 82.3 | 91.1 | 79.3 | 68.8 | --- |
| 61 | 720 | 670 | 754 | 81.8 | 90.7 | 78.4 | 67.7 | --- |
| 60 | 697 | 654 | 732 | 81.2 | 90.2 | 77.5 | 66.6 | --- |
| 59 | 674 | 634 | 710 | 80.7 | 89.8 | 76.6 | 65.5 | 351 (2420) |
| 58 | 653 | 615 | 690 | 80.1 | 89.3 | 75.7 | 64.3 | 338 (2330) |
| 57 | 633 | 595 | 670 | 79.6 | 88.9 | 74.8 | 63.2 | 325 (2240) |
| 56 | 613 | 577 | 650 | 79.0 | 88.3 | 73.9 | 62.0 | 313 (2160) |
| 55 | 595 | 560 | 630 | 78.5 | 87.9 | 73.0 | 60.9 | 301 (2070) |
| 54 | 577 | 543 | 612 | 78.0 | 87.4 | 72.0 | 59.8 | 292 (2010) |
| 53 | 560 | 525 | 594 | 77.4 | 86.9 | 71.2 | 58.6 | 283 (1950) |
| 52 | 544 | 512 | 576 | 76.8 | 86.4 | 70.2 | 57.4 | 273 (1880) |
| 51 | 528 | 496 | 558 | 76.3 | 85.9 | 69.4 | 56.1 | 264 (1820) |
| 50 | 513 | 482 | 542 | 75.9 | 85.5 | 68.5 | 55.0 | 255 (1760) |
| 49 | 498 | 468 | 526 | 75.2 | 85.0 | 67.6 | 53.8 | 246 (1700) |
| 48 | 484 | 455 | 510 | 74.7 | 84.5 | 66.7 | 52.5 | 238 (1640) |
| 47 | 471 | 442 | 495 | 74.1 | 83.9 | 65.8 | 51.4 | 229 (1580) |
| 46 | 458 | 432 | 480 | 73.6 | 83.5 | 64.8 | 50.3 | 221 (1520) |
| 45 | 446 | 421 | 466 | 73.1 | 83.0 | 64.0 | 49.0 | 215 (1480) |
| 44 | 434 | 409 | 452 | 72.5 | 82.5 | 63.1 | 47.8 | 208 (1430) |
| 43 | 423 | 400 | 438 | 72.0 | 82.0 | 62.2 | 46.7 | 201 (1390) |
| 42 | 412 | 390 | 426 | 71.5 | 81.5 | 61.3 | 45.5 | 194 (1340) |
| 41 | 402 | 381 | 414 | 70.9 | 80.9 | 60.4 | 44.3 | 188 (1300) |
| 40 | 392 | 371 | 402 | 70.4 | 80.4 | 59.5 | 43.1 | 182 (1250) |
| 39 | 382 | 362 | 391 | 69.9 | 79.9 | 58.6 | 41.9 | 177 (1220) |
| 38 | 372 | 353 | 380 | 69.4 | 79.4 | 57.7 | 40.8 | 171 (1180) |
| 37 | 363 | 344 | 370 | 68.9 | 78.8 | 56.8 | 39.6 | 166 (1140) |
| 36 | 354 | 336 | 360 | 68.4 | 78.3 | 55.9 | 38.4 | 161 (1110) |
| 35 | 345 | 327 | 351 | 67.9 | 77.7 | 55.0 | 37.2 | 156 (1080) |
| 34 | 336 | 319 | 342 | 67.4 | 77.2 | 54.2 | 36.1 | 152 (1050) |
| 33 | 327 | 311 | 334 | 66.8 | 76.6 | 53.3 | 34.9 | 149 (1030) |
| 32 | 318 | 301 | 326 | 66.3 | 76.1 | 52.1 | 33.7 | 146 (1010) |
| 31 | 310 | 294 | 318 | 65.8 | 75.6 | 51.3 | 32.5 | 141 (970) |
| 30 | 302 | 286 | 311 | 65.3 | 75.0 | 50.4 | 31.3 | 138 (950) |
| 29 | 294 | 279 | 304 | 64.6 | 74.5 | 49.5 | 30.1 | 135 (930) |
| 28 | 286 | 271 | 297 | 64.3 | 73.9 | 48.6 | 28.9 | 131 (900) |
| 27 | 279 | 264 | 290 | 63.8 | 73.3 | 47.7 | 27.8 | 128 (880) |
| 26 | 272 | 258 | 284 | 63.3 | 72.8 | 46.8 | 26.7 | 125 (860) |
| 25 | 266 | 253 | 278 | 62.8 | 72.2 | 45.9 | 25.5 | 123 (850) |
| 24 | 260 | 247 | 272 | 62.4 | 71.6 | 45.0 | 24.3 | 119 (820) |
| 23 | 254 | 243 | 266 | 62.0 | 71.0 | 44.0 | 23.1 | 117 (810) |
| 22 | 248 | 237 | 261 | 61.5 | 70.5 | 43.2 | 22.0 | 115 (790) |
| 21 | 243 | 231 | 256 | 61.0 | 69.9 | 42.3 | 20.7 | 112 (770) |
| 20 | 238 | 226 | 251 | 60.5 | 69.4 | 41.5 | 19.6 | 110 (760) |
|
A This table gives the approximate interrelationships of hardness values and approximate tensile strength of steels. It is possible that steels of various compositions and processing histories will deviate in hardness-tensile strength relationship from the data presented in this table. The data in this table should not be used for austenitic stainless steels, but have been shown to be applicable for ferritic and martensitic stainless steels. The data in this table should not be used to establish a relationship between hardness values and tensile strength of hard drawn wire. Where more precise conversions are required, they should be developed specially for each steel composition, heat treatment, and part. |
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| ASTM E 140 Hardness Conversion Tables for Metals | (Go To Page 2) |
| Conversion Tables for Hardness Scales-Cast Rolls | |
| Hardness Scales Conversion Table - Forged Rolls | |
| Steel Hardness Conversion Table |