Hardness Conversion Chart ROCKWELL ROCKWELL BRINELL VICKERS TENSILE PSI HARDNESS HARDNESS HARDNESS HARDNESS STRENGTH (1000lb/in2) (HRb) (HRc) (HB) (HV) (N/mm2) 67 – 121 122 401 58 70 – 126 127 432 63 73 – 132 132 448 65 75 – 136 137 455 66 77 – 140 143 463 67 80 – 147 150 479 69 82 – 153 156 494 72 84 – 159 163 525 76 86 – 165 171 540 78 89 – 177 178 556 81 91 – 186 188 602 88 93 – 197 196 632 92 96 – 216 212 664 97 97 – 223 218 695 101 98 21 230 234 756 110 – 22 236 241 772 112 – 23 242 247 787 114 – 24 248 255 818 118 – 25 254 261 849 123 – 27 266 269 865 125 – 28 272 275 895 130 – 29 278 284 911 132 – 30 284 292 942 136 – 31 293 300 973 141 – 32 302 308 988 143 – 33 310 318 1019 147 – 34 319 327 1050 152 – 35 328 337 1096 159 – 37 345 349 1127 163 – 38 353 359 1158 168 – 39 362 370 1189 172 – 40 370 381 1235 179 – 41 381 395 1266 183 – 42 391 408 1312 190 – 44 411 422 1359 197 – 45 422 437 1420 206 – 46 433 452 1467 212 – 48 455 470 1513 219 – 50 479 497 1559 226 – 51 485 517 1621 235 – 52 497 532 1668 241 – 54 – 573 1729 250 – 56 – 609 1807 262 – 57 – 630 1884 273 – 59 – 670 1961 284 – 60 – 698 2039 295 – 61 – 725 – – – 62 – 740 – – – 63 – 780 – – – 64 – 812 – – – 65 – 847 – – – 66 – 885 – – – 67 – 926 – – – 68 – 971 – – Conversions from each scale are approximate www.sgsmicrotools.com 151