Hardness ranges for heat treated steel
| Heat Treated Condition |
Q | R | S | T | U | V | W | X | Z |
|---|---|---|---|---|---|---|---|---|---|
| Tensile Strength |
625-775 n/mm2 | 700-850 n/mm2 | 775-925 n/mm2 | 850-1000 n/mm2 | 925-1075 n/mm2 | 1000-1150 n/mm2 | 1075-1225 n/mm2 |
1150-1300 n/mm2 |
1550 n/mm2 |
| Hardness Brinell |
179-229 | 201-225 | 223-277 | 248-302 | 269-331 | 293-352 | 311-375 | 345-401 | 444 |
| Reference Table: Steel hardness conversion chart – all values approximate. | ||||
|---|---|---|---|---|
| Brinell Hardness HB |
Rockwell HRC |
Rockwell HRB |
Vickers HV |
N/mm² |
| 800 | 72 | |||
| 780 | 71 | |||
| 760 | 70 | |||
| 752 | 69 | |||
| 745 | 68 | |||
| 746 | 67 | |||
| 735 | 66 | |||
| 711 | 65 | |||
| 695 | 64 | |||
| 681 | 63 | |||
| 658 | 62 | |||
| 642 | 61 | |||
| 627 | 60 | |||
| 613 | 59 | |||
| 601 | 58 | 746 | ||
| 592 | 57 | 727 | ||
| 572 | 56 | 694 | ||
| 552 | 55 | 649 | ||
| 534 | 54 | 120 | 589 | |
| 513 | 53 | 119 | 567 | |
| 504 | 52 | 118 | 549 | |
| 486 | 51 | 118 | 531 | |
| 469 | 50 | 117 | 505 | |
| 468 | 49 | 117 | 497 | |
| 456 | 48 | 116 | 490 | 1569 |
| 445 | 47 | 115 | 474 | 1520 |
| 430 | 46 | 115 | 458 | 1471 |
| 419 | 45 | 114 | 448 | 1447 |
| 415 | 44 | 114 | 438 | 1422 |
| 402 | 43 | 114 | 424 | 1390 |
| 388 | 42 | 113 | 406 | 1363 |
| 375 | 41 | 112 | 393 | 1314 |
| 373 | 40 | 111 | 388 | 1265 |
| 360 | 39 | 111 | 376 | 1236 |
| 348 | 38 | 110 | 361 | 1187 |
| 341 | 37 | 109 | 351 | 1157 |
| 331 | 36 | 109 | 342 | 1118 |
| 322 | 35 | 108 | 332 | 1089 |
| 314 | 34 | 108 | 320 | 1049 |
| 308 | 33 | 107 | 311 | 1035 |
| 300 | 32 | 107 | 303 | 1020 |
| 290 | 31 | 106 | 292 | 990 |
| 277 | 30 | 105 | 285 | 971 |
| 271 | 29 | 104 | 277 | 941 |
| 264 | 28 | 103 | 271 | 892 |
| 262 | 27 | 103 | 262 | 880 |
| 255 | 26 | 102 | 258 | 870 |
| 250 | 25 | 101 | 255 | 853 |
| 245 | 24 | 100 | 252 | 838 |
| 240 | 23 | 100 | 247 | 824 |
| 233 | 22 | 99 | 241 | 794 |
| 229 | 21 | 98 | 235 | 775 |
| 223 | 20 | 97 | 227 | 755 |
| 216 | 19 | 96 | 222 | 716 |
| 212 | 18 | 95 | 218 | 706 |
| 208 | 17 | 95 | 210 | 696 |
| 203 | 16 | 94 | 201 | 680 |
| 199 | 15 | 93 | 199 | 667 |
| 191 | 14 | 92 | 197 | 657 |
| 190 | 13 | 92 | 186 | 648 |
| 186 | 12 | 91 | 184 | 637 |
| 183 | 11 | 90 | 183 | 617 |
| 180 | 10 | 89 | 180 | 608 |
| 175 | 9 | 88 | 178 | 685 |
| 170 | 7 | 87 | 175 | 559 |
| 167 | 6 | 86 | 172 | 555 |
| 166 | 5 | 86 | 168 | 549 |
| 163 | 4 | 85 | 162 | 539 |
| 160 | 3 | 84 | 160 | 535 |
| 156 | 2 | 83 | 158 | 530 |
| 154 | 1 | 82 | 152 | 515 |
| 149 | 81 | 149 | 500 | |
| 147 | 80 | 147 | 490 | |
| 143 | 79 | 146 | 482 | |
| 141 | 78 | 144 | 481 | |
| 139 | 77 | 142 | 480 | |
| 137 | 76 | 140 | 475 | |
| 135 | 75 | 137 | 467 | |
| 131 | 74 | 134 | 461 | |
| 127 | 72 | 129 | 451 | |
| 121 | 70 | 127 | 431 | |
| 116 | 68 | 124 | 422 | |
| 114 | 67 | 121 | 412 | |
| 111 | 66 | 118 | 402 | |
| 107 | 64 | 115 | 382 | |
| 105 | 62 | 112 | 378 | |
| 103 | 61 | 108 | 373 | |
| 95 | 56 | 104 | ||
| 90 | 52 | 95 | ||
| 81 | 41 | 85 | ||
| 76 | 37 | 80 | ||
| Brinell HB |
Rockwell HRC |
Rockwell HRB |
Vickers HV |
N/mm² |
| 3000kg 10mm Ball |
150kg Brale |
100kg 1/16″ Ball |
Diamond Pyramid 120kg |
Tensile strength (Approx) |
| Reference table: Steel Hardness conversion chart
Since the various types of hardness tests do not all measure the same combination of material properties, conversion from one hardness scale to another is only an approximate process. Because of the wide range of variation among different materials, it is not possible to state confidence limits for the errors in using a conversion chart. |
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