CONTACT HEICO TO REQUEST A QUOTE TODAY!
© 2021 HEICO Fastening Systems. All rights reserved. | Site Map | Website Design by m.e.
Below are approximate equivalent hardness numbers for carbon and alloy steels.
Chart courtesy of the Collaboration for NDT/NDE Education led by the Center for NDE at Iowa State University.
| Rockwell | Rockwell | Rockwell | Rockwell | Rockwell Superficial | Rockwell Superficial | Rockwell Superficial | Brinell | Vickers | Knoop | Sleroscope | Approx. Tensile Strength of Steel (PSI) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| A Scale 60kg Diam. Brale | B Scale 100kg 1/16″ Ball | C Scale 150kg Diam. Brale | D Scale 100kg Diam. Brale | 15N Scale 15kg Diam. Brale | 30N Scale 30kg Diam. Brale | 45N Scale 45kg Diam. Brale | 3000kg 10mm Ball | 500g or Greater Load | |||
| – | – | 80 | 87 | 97 | 92 | 87 | – | 1865 | – | – | – |
| 92 | – | 79 | 86 | – | 92 | 87 | – | 1787 | – | – | – |
| 91 | – | 78 | 85 | 96 | 91 | 86 | – | 1710 | – | – | – |
| 91 | – | 77 | 84 | – | 91 | 85 | – | 1633 | – | – | – |
| 90 | – | 76 | 83 | 96 | 90 | 84 | – | 1556 | – | – | – |
| 90 | – | 75 | 83 | – | 89 | 83 | – | 1478 | – | – | – |
| 89 | – | 74 | 82 | 95 | 89 | 82 | – | 1400 | – | – | – |
| 89 | – | 73 | 81 | – | 88 | 81 | – | 1323 | – | – | – |
| 88 | – | 72 | 80 | 95 | 87 | 80 | – | 1245 | – | – | – |
| 87 | – | 71 | 80 | – | 87 | 79 | – | 1160 | – | – | – |
| 87 | – | 70 | 79 | 94 | 86 | 78 | – | 1076 | – | 99 | – |
| 86 | – | 69 | 78 | – | 85 | 77 | – | 1004 | – | 98 | – |
| 85.6 | – | 68 | 76.9 | 93.2 | 84.4 | 75.4 | – | 940 | 920 | 97 | – |
| 85.3 | – | 67.5 | 76.5 | 93 | 84 | 74.8 | – | 920 | 908 | 96 | – |
| 85 | – | 66.4 | 76.1 | 92.9 | 83.6 | 74.2 | – | 900 | 895 | 95 | – |
| 84.7 | – | 65.9 | 75.7 | 92.7 | 83.1 | 73.6 | – | 880 | 882 | 93 | – |
| 84.4 | – | 65.3 | 75.3 | 92.5 | 82.7 | 73.1 | – | 860 | 867 | 92 | – |
| 84.1 | – | 64.7 | 74.8 | 92.3 | 82.2 | 72.2 | – | 840 | 852 | 91 | – |
| 83.8 | – | 64 | 74.3 | 92.1 | 81.7 | 71.8 | 745* | 820 | 837 | 90 | – |
| 83.4 | – | 63.3 | 73.8 | 91.8 | 81.1 | 71 | – | 800 | 822 | 88 | – |
| 83 | – | 62.5 | 73.3 | 91.5 | 80.4 | 70.2 | – | 780 | 806 | 87 | – |
| 82.6 | – | 61.8 | 72.6 | 91.2 | 79.7 | 69.4 | 710* | 760 | 788 | 86 | – |
| 82.2 | – | 61 | 72.1 | 91 | 79.1 | 68.6 | – | 740 | 772 | 84 | – |
| 81.8 | – | 60.1 | 71.5 | 90.7 | 78.4 | 67.7 | – | 720 | 754 | 83 | – |
| 81.3 | – | 59.7 | 70.8 | 90.3 | 77.6 | 66.7 | 653* | 700 | 735 | 81 | – |
| 81.1 | – | 59.2 | 70.5 | 90.1 | 77.2 | 66.2 | – | 690 | 725 | – | – |
| 80.8 | – | 58.8 | 70.1 | 89.8 | 76.8 | 65.7 | – | 680 | 716 | 80 | 329,000 |
| 80.6 | – | 58.3 | 69.8 | 89.7 | 76.4 | 65.3 | – | 670 | 706 | – | 324,000 |
| 80.3 | – | 57.8 | 69.4 | 89.5 | 75.9 | 64.7 | 620* | 660 | 697 | 79 | – |
| 80 | – | 57.3 | 69 | 89.2 | 75.5 | 64.1 | 611* | 650 | 687 | 78 | – |
| 79.8 | – | 56.8 | 68.7 | 89 | 75.1 | 63.5 | 601* | 640 | 677 | 77 | 309,000 |
| 79.5 | – | 56.3 | 68.3 | 88.8 | 74.6 | 63 | 591* | 630 | 667 | 76 | – |
| 79.2 | – | 55.7 | 67.9 | 88.5 | 74.2 | 62.4 | 582* | 620 | 657 | 75 | 297,000 |
| 78.9 | – | 55.2 | 67.5 | 88.2 | 73.6 | 61.7 | 573* | 610 | 646 | – | – |
| 78.6 | – | 54.7 | 67 | 88 | 73.2 | 61.2 | 564* | 600 | 636 | 74 | – |
| 78.4 | – | 54.1 | 66.7 | 87.8 | 72.7 | 60.5 | 554* | 590 | 625 | 73 | 285,000 |
| 78 | – | 53.6 | 66.2 | 87.5 | 72.1 | 59.9 | 545* | 580 | 615 | 72 | – |
| 77.8 | – | 53 | 65.8 | 87.2 | 71.7 | 59.3 | 535* | 570 | 604 | – | 274,000 |
| 77.4 | – | 52.3 | 65.4 | 86.9 | 71.2 | 58.6 | 525* | 560 | 594 | 71 | – |
| 77 | – | 51.7 | 64.8 | 86.6 | 70.5 | 57.8 | 517* | 550 | 583 | 70 | 263,000 |
| 76.7 | – | 51.1 | 64.4 | 86.3 | 70 | 57 | 507* | 540 | 572 | 69 | – |
| 76.4 | – | 50.5 | 63.9 | 86 | 69.5 | 56.2 | 497* | 530 | 561 | 68 | 253,000 |
| 76.1 | – | 49.8 | 63.5 | 85.7 | 69 | 55.6 | 488* | 520 | 550 | 67 | – |
| 75.7 | – | 49.1 | 62.9 | 85.4 | 68.3 | 54.7 | 479* | 510 | 539 | – | 243,000 |
| 75.3 | – | 48.4 | 62.2 | 85 | 67.7 | 53.9 | 471* | 500 | 528 | 66 | – |
| 74.9 | – | 47.7 | 61.6 | 84.7 | 67.1 | 53.1 | 460* | 490 | 517 | 65 | 235,000 |
| 74.5 | – | 46.9 | 61.3 | 84.3 | 66.4 | 52.2 | 452* | 480 | 505 | 64 | – |
| 74.1 | – | 46.1 | 60.7 | 83.9 | 65.7 | 51.3 | 441 | 470 | 494 | – | – |
| 73.6 | – | 45.3 | 60.1 | 83.6 | 64.9 | 50.4 | 433 | 460 | 482 | 62 | 210,000 |
| 73.3 | – | 44.5 | 59.4 | 83.2 | 64.3 | 49.4 | 425 | 450 | 471 | – | – |
| 72.8 | – | 43.6 | 58.8 | 82.8 | 63.5 | 48.4 | 415 | 440 | 459 | 59 | – |
| 72.3 | – | 42.7 | 58.2 | 82.3 | 62.7 | 47.4 | 405 | 430 | 447 | 58 | 195,000 |
| 71.8 | – | 41.8 | 57.5 | 81.8 | 61.9 | 46.4 | 397 | 420 | 435 | 57 | – |
| 71.4 | – | 40.8 | 56.8 | 81.4 | 61.1 | 45.3 | 388 | 410 | 423 | 56 | – |
| 70.8 | – | 39.8 | 56 | 80.8 | 60.2 | 44.1 | 379 | 400 | 412 | 55 | – |
| 70.3 | – | 38.8 | 55.2 | 80.3 | 59.3 | 42.9 | 369 | 390 | 400 | – | 176,000 |
| 69.8 | – | 37.7 | 54.4 | 79.8 | 58.4 | 41.7 | 360 | 380 | 389 | 50 | – |
| 69.2 | – | 36.6 | 53.6 | 79.2 | 57.4 | 40.4 | 350 | 370 | 378 | 51 | 166,000 |
| 68.7 | – | 35.5 | 52.8 | 78.6 | 56.4 | 39.1 | 341 | 360 | 367 | 50 | – |
| 68.1 | – | 34.4 | 51.9 | 78 | 55.4 | 37.8 | 331 | 350 | 356 | 48 | – |
| 67.6 | – | 33.3 | 51.1 | 77.4 | 54.4 | 36.5 | 322 | 340 | 346 | 47 | – |
| 67 | – | 32.2 | 50.2 | 76.8 | 53.6 | 35.2 | 313 | 330 | 337 | 46 | – |
| 66.4 | – | 31 | 49.4 | 76.2 | 52.3 | 33.9 | 303 | 320 | 328 | 45 | 150,000 |
| 65.8 | – | 29.8 | 48.4 | 75.6 | 51.3 | 32.5 | 294 | 310 | 318 | – | – |
| 65.2 | – | 29.2 | 47.5 | 74.9 | 50.2 | 31.1 | 284 | 300 | 309 | 42 | 141,000 |
| 64.8 | – | 28.5 | 47.1 | 74.6 | 49.7 | 30.4 | 280 | 295 | 305 | – | – |
| 64.5 | – | 27.8 | 46.5 | 74.2 | 49 | 29.5 | 275 | 290 | 300 | 41 | – |
| 64.2 | – | 27.1 | 46 | 73.8 | 48.4 | 28.7 | 270 | 285 | 296 | – | 133,000 |
| 63.8 | – | 26.4 | 45.3 | 73.4 | 47.8 | 27.9 | 265 | 280 | 291 | 40 | – |
| 63.5 | – | 25.6 | 44.9 | 73 | 47.2 | 27.1 | 261 | 275 | 286 | 39 | 129,000 |
| 63.1 | – | 24.8 | 44.3 | 72.6 | 46.4 | 26.2 | 256 | 270 | 282 | 38 | – |
| 62.7 | – | 24 | 43.7 | 72.1 | 45.7 | 25.2 | 252 | 265 | 277 | – | – |
| 62.4 | – | 23.1 | 43.1 | 71.6 | 45 | 24.3 | 247 | 260 | 272 | 37 | 122,000 |
| 62 | – | 22.2 | 42.2 | 71.1 | 44.2 | 23.2 | 243 | 255 | 267 | – | – |
| 61.6 | 99.5 | 21.3 | 41.7 | 70.6 | 43.4 | 22.2 | 238 | 250 | 262 | 36 | – |
| 61.2 | – | 20.3 | 41.1 | 70.1 | 42.5 | 21.1 | 233 | 245 | 258 | 35 | 115,000 |
| 60.7 | 98.1 | – | 40.3 | 69.6 | 41.7 | 19.9 | 228 | 240 | 253 | 34 | – |
| – | – | – | – | – | – | – | – | 235 | – | – | – |
| – | 96.7 | – | – | – | – | – | 219 | 230 | 243 | 33 | 105,000 |
| – | – | – | – | – | – | – | – | 225 | – | – | – |
| – | 95 | – | – | – | – | – | 209 | 220 | 234 | 32 | 100,000 |
| – | – | – | – | – | – | – | – | 215 | – | – | – |
| – | 93.4 | – | – | – | – | – | 200 | 210 | 226 | 30 | 98,000 |
| – | – | – | – | – | – | – | – | 205 | – | – | – |
| – | 91.5 | – | – | – | – | – | 190 | 200 | 216 | 29 | – |
| – | – | – | – | – | – | – | – | 195 | – | – | 90,000 |
| – | 89.5 | – | – | – | – | – | 181 | 190 | 206 | 28 | – |
| – | – | – | – | – | – | – | – | 185 | – | – | – |
| – | 87.1 | – | – | – | – | – | 171 | 180 | 196 | 26 | 83,000 |
| – | – | – | – | – | – | – | – | 175 | – | – | – |
| – | 85 | – | – | – | – | – | 162 | 170 | 185 | 25 | 79,0000 |
| – | – | – | – | – | – | – | – | 165 | – | – | – |
| – | 81.7 | – | – | – | – | – | 152 | 160 | 175 | 23 | – |
| – | – | – | – | – | – | – | – | 155 | – | – | – |
| – | 78.7 | – | – | – | – | – | 143 | 150 | 164 | 22 | 71,000 |
| – | – | – | – | – | – | – | – | 145 | – | – | – |
| – | 75 | – | – | – | – | – | 133 | 140 | 154 | 21 | – |
| – | – | – | – | – | – | – | – | 135 | – | – | – |
| – | 71.2 | – | – | – | – | – | 124 | 130 | 143 | 20 | 63,000 |
| – | – | – | – | – | – | – | – | 125 | – | – | – |
| – | 66.7 | – | – | – | – | – | 114 | 120 | 133 | 18 | – |
| – | – | – | – | – | – | – | – | 115 | – | – | 56,000 |
| – | 62.3 | – | – | – | – | – | 105 | 110 | 123 | – | – |
| – | – | – | – | – | – | – | – | 105 | – | – | – |
| – | 56.2 | – | – | – | – | – | 95 | 100 | 112 | – | – |
| – | 52 | – | – | – | – | – | 90 | 95 | 107 | – | – |
| – | 48 | – | – | – | – | – | 86 | 90 | 102 | – | – |
| – | 41 | – | – | – | – | – | 81 | 85 | 97 | – | – |