HARDNESS CONVERSION FOR CARBON AND ALLOY STEELS
Note: All Values Are Approximate |
Brinell Hardness Number (Carbide Ball) |
Rockwell Hardness Numbers |
Tensile Strength |
|||||
C Scale |
A Scale |
15N Scale Superficial |
B Scale |
30T Scale Superficial |
|||
ksi | MPa |
– | 66 | 84.5 | 92.5 | – | – | – | – |
722 | 64 | 83.4 | 91.8 | – | – | – | – |
688 | 62 | 82.3 | 91.1 | – | – | – | – |
654 | 60 | 81.2 | 90.2 | – | – | – | – |
615 | 58 | 80.1 | 89.3 | – | – | – | – |
577 | 56 | 79.0 | 88.3 | – | – | 313 | 2160 |
543 | 54 | 78.0 | 87.4 | – | – | 292 | 2010 |
512 | 52 | 76.8 | 86.4 | – | – | 273 | 1880 |
481 | 50 | 75.9 | 85.5 | – | – | 255 | 1760 |
455 | 48 | 74.7 | 84.5 | – | – | 238 | 1640 |
443 | 47 | 74.1 | 83.9 | – | – | 229 | 1580 |
432 | 46 | 73.6 | 83.5 | – | – | 221 | 1520 |
421 | 45 | 73.1 | 83.0 | – | – | 215 | 1480 |
409 | 44 | 72.5 | 82.5 | – | – | 208 | 1430 |
400 | 43 | 72.0 | 82.0 | – | – | 201 | 1390 |
390 | 42 | 71.5 | 81.5 | – | – | 194 | 1340 |
381 | 41 | 70.9 | 80.9 | – | – | 188 | 1300 |
371 | 40 | 70.4 | 80.4 | – | – | 182 | 1250 |
362 | 39 | 69.9 | 79.9 | – | – | 177 | 1220 |
353 | 38 | 69.4 | 79.4 | – | – | 171 | 1180 |
344 | 37 | 68.9 | 78.8 | – | – | 166 | 1140 |
336 | 36 | 68.4 | 78.3 | – | – | 161 | 1110 |
327 | 35 | 67.9 | 77.7 | – | – | 156 | 1080 |
319 | 34 | 67.4 | 77.2 | – | – | 153 | 1050 |
311 | 33 | 66.8 | 76.6 | – | – | 149 | 1030 |
301 | 32 | 66.3 | 76.1 | – | – | 146 | 1010 |
294 | 31 | 65.8 | 75.6 | – | – | 141 | 970 |
286 | 30 | 65.3 | 75.0 | – | – | 138 | 950 |
279 | 29 | 64.6 | 74.5 | – | – | 135 | 930 |
271 | 28 | 64.3 | 73.9 | – | – | 131 | 900 |
264 | 27 | 63.8 | 73.3 | – | – | 128 | 880 |
258 | 26 | 63.3 | 72.8 | – | – | 125 | 860 |
253 | 25 | 62.8 | 72.2 | – | – | 123 | 850 |
247 | 24 | 62.4 | 71.6 | – | – | 119 | 820 |
243 | 23 | 62.0 | 71.0 | – | – | 117 | 810 |
240 | – | – | – | 100 | 83.1 | 116 | 800 |
234 | – | – | – | 99 | 82.5 | 114 | 785 |
222 | – | – | – | 97 | 81.1 | 104 | 715 |
210 | – | – | – | 95 | 79.8 | 100 | 690 |
200 | – | – | – | 93 | 78.4 | 94 | 650 |
195 | – | – | – | 92 | 77.8 | 92 | 635 |
185 | – | – | – | 90 | 76.4 | 89 | 615 |
176 | – | – | – | 88 | 75.1 | 86 | 590 |
169 | – | – | – | 86 | 73.8 | 83 | 570 |
162 | – | – | – | 84 | 72.4 | 81 | 560 |
156 | – | – | – | 82 | 71.1 | 77 | 530 |
150 | – | – | – | 80 | 69.7 | 72 | 495 |
144 | – | – | – | 78 | 68.4 | 69 | 475 |
139 | – | – | – | 76 | 67.1 | 67 | 460 |
135 | – | – | – | 74 | 65.7 | 65 | 450 |
130 | – | – | – | 72 | 64.4 | 63 | 435 |
125 | – | – | – | 70 | 63.1 | 61 | 420 |
121 | – | – | – | 68 | 61.7 | 59 | 405 |
117 | – | – | – | 66 | 60.4 | 57 | 395 |
114 | – | – | – | 64 | 59.0 | – | – |