Hardness Table
ROCKWELL | SUPERFICIAL ROCKWELL | BRINELL | VICKERS OR FIRTH DIAMOND HARDNESS NUMBER | SCLERO- SCOPE | TENSILE STRENGTH | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
10 m/m Ball | |||||||||||
Diamond Brale | 1/16" Bull | "N" Brale Penetrater | 3000 kgm Load | ||||||||
150 kgm C Scale | 60 kgm A Scale | 100 kgm D Scale | 100 kgm B Scale | 15 kg Load 15 N | 30 kg Load 30N | 45 kg Load 45N | Diam. Of Ball Impression in m/m | Hardness Number | Equivalent 1000 lb. Sq. In. | ||
80 | 92 | 87 | 97 | 92 | 87 | 1865 | |||||
79 | 92 | 86 | 92 | 87 | 1787 | ||||||
78 | 91 | 85 | 96 | 91 | 86 | 1710 | |||||
77 | 91 | 84 | 91 | 85 | 1633 | ||||||
76 | 90 | 83 | 96 | 90 | 84 | 1556 | |||||
75 | 90 | 83 | 89 | 83 | 1478 | ||||||
74 | 89 | 82 | 95 | 89 | 82 | 1400 | |||||
73 | 89 | 81 | 88 | 81 | 1323 | ||||||
72 | 88 | 80 | 95 | 87 | 80 | 1245 | |||||
71 | 87 | 80 | 87 | 79 | 1160 | 99 | |||||
70 | 87 | 79 | 94 | 86 | 78 | 1076 | 98 | ||||
69 | 86 | 78 | 94 | 85 | 77 | 1004 | 97 | ||||
68 | 86 | 77 | 85 | 79 | 942 | 96 | |||||
67 | 85 | 76 | 93 | 84 | 75 | 894 | 95 | ||||
66 | 85 | 76 | 93 | 83 | 73 | 854 | 93 | ||||
65 | 84 | 75 | 92 | 82 | 72 | 2.25 | 745 | 820 | 91 | ||
64 | 84 | 74 | 81 | 74 | 2.3 | 710 | 789 | 88 | |||
63 | 83 | 73 | 92 | 80 | 70 | 2.3 | 710 | 763 | 87 | ||
62 | 83 | 73 | 91 | 79 | 69 | 2.35 | 682 | 746 | 85 | ||
61 | 82 | 72 | 91 | 79 | 68 | 2.35 | 682 | 720 | 83 | ||
60 | 81 | 71 | 90 | 78 | 67 | 2.4 | 653 | 697 | 82 | ||
59 | 81 | 70 | 90 | 77 | 66 | 2.45 | 627 | 674 | 80 | 326 | |
58 | 80 | 69 | 89 | 76 | 65 | 2.55 | 578 | 653 | 78 | 315 | |
57 | 80 | 69 | 89 | 75 | 63 | 2.55 | 578 | 633 | 77 | 304 | |
56 | 79 | 68 | 88 | 74 | 62 | 2.6 | 555 | 613 | 75 | 294 | |
55 | 79 | 67 | 88 | 73 | 61 | 2.6 | 555 | 595 | 74 | 287 | |
54 | 78 | 66 | 87 | 72 | 60 | 2.65 | 534 | 577 | 72 | 279 | |
53 | 77 | 65 | 87 | 71 | 59 | 2.7 | 514 | 560 | 71 | 269 | |
52 | 77 | 65 | 86 | 70 | 57 | 2.75 | 495 | 544 | 69 | 261 | |
51 | 76 | 64 | 86 | 69 | 56 | 2.75 | 495 | 528 | 68 | 254 | |
50 | 76 | 63 | 86 | 69 | 55 | 2.8 | 477 | 513 | 67 | 245 | |
49 | 75 | 62 | 85 | 68 | 54 | 2.85 | 461 | 498 | 65 | 238 | |
48 | 75 | 61 | 85 | 67 | 53 | 2.9 | 444 | 484 | 64 | 232 | |
47 | 74 | 61 | 84 | 66 | 51 | 2.9 | 444 | 471 | 63 | 225 | |
46 | 73 | 60 | 84 | 65 | 50 | 2.95 | 432 | 458 | 62 | 219 | |
45 | 73 | 59 | 83 | 64 | 49 | 3 | 415 | 446 | 61 | 211 | |
44 | 73 | 59 | 83 | 63 | 48 | 3 | 415 | 434 | 59 | 206 | |
43 | 72 | 58 | 82 | 62 | 47 | 3.05 | 401 | 423 | 58 | 202 | |
42 | 72 | 57 | 82 | 61 | 46 | 3.1 | 388 | 412 | 56 | 198 | |
41 | 71 | 56 | 81 | 60 | 44 | 3.1 | 388 | 402 | 55 | 191 | |
40 | 70 | 55 | 80 | 60 | 43 | 3.15 | 375 | 392 | 54 | 185 | |
39 | 70 | 55 | 80 | 59 | 42 | 3.2 | 363 | 382 | 53 | 181 | |
38 | 69 | 54 | 79 | 58 | 41 | 3.25 | 352 | 372 | 51 | 176 | |
37 | 69 | 53 | 109 | 79 | 57 | 40 | 3.3 | 341 | 363 | 50 | 171 |
36 | 68 | 52 | 109 | 78 | 56 | 39 | 3.35 | 331 | 354 | 49 | 168 |
35 | 68 | 52 | 108 | 78 | 55 | 37 | 3.35 | 331 | 345 | 48 | 163 |
34 | 67 | 51 | 108 | 77 | 54 | 36 | 3.4 | 321 | 336 | 46 | 159 |
33 | 67 | 50 | 107 | 77 | 53 | 38 | 3.45 | 311 | 327 | 45 | 154 |
32 | 66 | 49 | 106 | 76 | 52 | 34 | 3.5 | 302 | 318 | 44 | 150 |
31 | 66 | 48 | 106 | 76 | 51 | 33 | 3.55 | 293 | 310 | 43 | 146 |
30 | 65 | 48 | 105 | 75 | 50 | 32 | 3.6 | 285 | 302 | 42 | 142 |
29 | 65 | 47 | 104 | 75 | 50 | 30 | 3.65 | 277 | 294 | 41 | 138 |
28 | 64 | 46 | 103 | 74 | 49 | 29 | 3.7 | 269 | 286 | 40 | 134 |
27 | 64 | 45 | 103 | 73 | 48 | 28 | 3.75 | 262 | 279 | 39 | 131 |
26 | 63 | 45 | 102 | 73 | 47 | 27 | 3.8 | 255 | 272 | 38 | 126 |
25 | 63 | 44 | 101 | 72 | 46 | 26 | 3.8 | 255 | 266 | 37 | 124 |
24 | 62 | 43 | 100 | 72 | 45 | 24 | 3.85 | 248 | 260 | 37 | 122 |
23 | 62 | 42 | 99 | 71 | 44 | 23 | 3.9 | 241 | 254 | 36 | 118 |
22 | 62 | 42 | 99 | 71 | 43 | 22 | 3.95 | 235 | 248 | 35 | 116 |
21 | 61 | 41 | 98 | 70 | 42 | 21 | 4 | 229 | 243 | 35 | 113 |
20 | 61 | 40 | 97 | 69 | 42 | 20 | 4.05 | 223 | 238 | 34 | 111 |
18 | 95 | 4.1 | 217 | 230 | 33 | 107 | |||||
16* | 94 | 4.15 | 212 | 222 | 32 | 102 | |||||
14* | 92 | 4.25 | 203 | 213 | 31 | 98 | |||||
12* | 90 | 4.35 | 192 | 204 | 29 | 92 | |||||
10* | 89 | 4.4 | 187 | 195 | 28 | 90 | |||||
8* | 87 | 4.5 | 179 | 187 | 27 | 87 | |||||
6* | 85 | 4.6 | 170 | 180 | 26 | 83 | |||||
4* | 84 | 4.65 | 166 | 173 | 25 | 79 | |||||
2* | 82 | 4.8 | 156 | 166 | 25 | 77 | |||||
0* | 81 | 4.8 | 156 | 160 | 25 | 74 | |||||
79 | 4.9 | 149 | 156 | 23 | 73 | ||||||
77 | 5 | 143 | 150 | 22 | 70 | ||||||
74 | 5.1 | 137 | 143 | 21 | 67 | ||||||
72 | 5.2 | 131 | 137 | 65 | |||||||
70 | 5.3 | 126 | 132 | 20 | 62 | ||||||
68 | 5.4 | 121 | 127 | 19 | 60 | ||||||
65 | 5.5 | 116 | 122 | 18 | 58 | ||||||
5.6 | 112 | 117 | 15 | 56 |