Hardness Conversion Table
Hardness Conversion Table ASTM
Rockwell C Hardness Range
Approximate Hardness Conversion Numbers for Non-Austenitic Steels, According to ASTM E-140 The Conversion Values contained herein should be considered approximate only and may be inaccurate for specific applications
C | A | D | 15N | 30N | 45N | Vickers | Brinell | Tensile |
150 kgf | 60 kgf | 100 kgf | 15 kgf | 30 kgf | 45 kgf | Hardness | Hardness | Strength |
diamond | diamond | diamond | diamond | diamond | diamond | 3000 kgf 10mm ball | 1000 lbs/square in | |
68 | 85.6 | 76.9 | 93.2 | 84.4 | 75.4 | 940 | .. | .. |
67 | 85.0 | 76.1 | 92.9 | 83.6 | 74.2 | 900 | .. | .. |
66 | 84.5 | 75.4 | 92.5 | 82.8 | 73.3 | 865 | .. | .. |
65 | 83.9 | 74.5 | 92.2 | 81.9 | 72.0 | 832 | (739) | |
64 | 83.4 | 73.8 | 91.8 | 81.1 | 71.0 | 800 | (722) | |
63 | 82.8 | 73.0 | 91.4 | 80.1 | 69.9 | 772 | (705) | |
62 | 82.3 | 72.2 | 91.1 | 79.3 | 68.8 | 745 | (688) | |
61 | 81.8 | 71.5 | 90.7 | 78.4 | 67.7 | 720 | (670) | |
60 | 81.2 | 70.7 | 90.2 | 77.5 | 66.6 | 697 | (654) | |
59 | 80.7 | 69.9 | 89.8 | 76.6 | 65.5 | 674 | (634) | 351 |
58 | 80.1 | 69.2 | 89.3 | 75.7 | 64.3 | 653 | 615 | 338 |
57 | 79.6 | 68.5 | 88.9 | 74.8 | 63.2 | 633 | 595 | 325 |
56 | 79.0 | 67.7 | 88.3 | 73.9 | 62.0 | 613 | 577 | 313 |
55 | 78.5 | 66.9 | 87.9 | 73.0 | 60.9 | 595 | 560 | 301 |
54 | 78.0 | 66.1 | 87.4 | 72.0 | 59.8 | 577 | 543 | 292 |
53 | 77.4 | 65.4 | 86.9 | 71.2 | 58.6 | 560 | 525 | 283 |
52 | 76.8 | 64.6 | 84.4 | 70.2 | 57.4 | 544 | 512 | 273 |
51 | 76.3 | 63.8 | 85.9 | 69.4 | 56.1 | 528 | 496 | 264 |
50 | 75.9 | 63.1 | 85.5 | 68.5 | 55.0 | 513 | 481 | 255 |
49 | 75.2 | 62.1 | 85.0 | 67.6 | 53.8 | 498 | 469 | 246 |
48 | 74.7 | 61.4 | 84.6 | 66.7 | 52.5 | 484 | 455 | 237 |
47 | 74.1 | 60.8 | 83.9 | 65.8 | 51.4 | 471 | 443 | 229 |
46 | 73.6 | 60.0 | 83.5 | 64.8 | 50.3 | 458 | 432 | 221 |
45 | 73.1 | 59.2 | 83.0 | 64.0 | 49.0 | 446 | 421 | 215 |
44 | 72.5 | 58.5 | 82.5 | 63.1 | 47.8 | 434 | 409 | 208 |
43 | 72.0 | 57.7 | 82.0 | 62.2 | 46.7 | 423 | 400 | 201 |
42 | 71.5 | 56.9 | 81.5 | 61.3 | 45.5 | 412 | 390 | 195 |
41 | 70.9 | 56.2 | 80.9 | 60.4 | 44.3 | 402 | 381 | 188 |
40 | 70.4 | 55.4 | 80.4 | 59.5 | 43.1 | 392 | 371 | 182 |
39 | 69.9 | 54.6 | 79.9 | 58.6 | 41.9 | 382 | 362 | 177 |
38 | 69.4 | 53.8 | 79.4 | 57.7 | 40.8 | 372 | 353 | 171 |
37 | 58.9 | 53.1 | 78.8 | 56.8 | 39.6 | 363 | 344 | 166 |
36 | 68.4 | 52.3 | 78.3 | 55.9 | 38.4 | 354 | 336 | 161 |
35 | 67.9 | 51.5 | 77.7 | 55.0 | 37.2 | 345 | 327 | 156 |
34 | 67.4 | 50.8 | 77.2 | 54.2 | 36.1 | 336 | 319 | 152 |
33 | 66.8 | 50.0 | 76.6 | 53.3 | 34.9 | 327 | 311 | 149 |
32 | 66.3 | 49.2 | 76.1 | 52.1 | 33.7 | 318 | 301 | 146 |
31 | 65.8 | 48.4 | 75.6 | 51.3 | 32.5 | 310 | 294 | 141 |
30 | 65.3 | 47.7 | 75.0 | 50.4 | 31.3 | 302 | 286 | 138 |
29 | 64.8 | 47.0 | 74.5 | 49.5 | 30.1 | 294 | 279 | 135 |
28 | 64.3 | 46.1 | 73.9 | 48.6 | 28.9 | 286 | 271 | 131 |
27 | 63.8 | 45.2 | 73.3 | 47.7 | 27.8 | 279 | 264 | 128 |
26 | 63.3 | 44.6 | 72.8 | 46.8 | 26.7 | 272 | 258 | 125 |
25 | 62.8 | 43.8 | 72.2 | 45.9 | 25.5 | 266 | 253 | 123 |
24 | 62.4 | 43.1 | 71.6 | 45.0 | 24.3 | 260 | 247 | 119 |
23 | 62.0 | 42.1 | 71.0 | 44.0 | 23.1 | 254 | 243 | 117 |
22 | 61.5 | 41.6 | 70.5 | 43.2 | 22.0 | 248 | 237 | 115 |
21 | 61.0 | 40.9 | 69.9 | 42.3 | 20.7 | 243 | 231 | 112 |
20 | 60.5 | 40.1 | 69.4 | 41.5 | 19.6 | 238 | 226 | 110 |
Rockwell B Hardness Range
Approximate Hardness Conversion Numbers for Non-Austenitic Steels, according to ASTM E-140 The conversion values contained herein should be considered approximate only and may be inaccurate for specific applications.
Rockwell | Superficial Rockwell | Vickers | Brinell | Tensile | Brinelll | ||||
B | A | E | 15T | 30T | 45T | Hardness | Hardness | Strength | Hardness |
100 kgf | 60 kgf | 100 kgf | 15 kgf | 30 kgf | 45 kgf | 3000 kgf | 1000 lbs/ | 500 kgf | |
1/16″ ball | diamond | 1/8″ ball | 1/16″ ball | 1/16″ ball | 1/16″ ball | 10mm ball | square in | 10mm ball | |
100 | 61.5 | 93.1 | 83.1 | 72.9 | 240 | 240 | 116 | 201 | |
99 | 60.9 | 82.8 | 82.5 | 71.9 | 234 | 234 | 114 | 195 | |
98 | 60.2 | 92.5 | 81.8 | 70.9 | 228 | 228 | 109 | 189 | |
97 | 59.5 | 92.1 | 81.1 | 69.9 | 222 | 222 | 105 | 184 | |
96 | 58.9 | 91.8 | 80.4 | 68.9 | 216 | 216 | 102 | 179 | |
95 | 58.3 | 91.5 | 79.8 | 67.9 | 210 | 210 | 100 | 175 | |
94 | 57.6 | 91.2 | 79.1 | 66.9 | 205 | 205 | 98 | 171 | |
93 | 57.0 | 90.8 | 78.4 | 65.9 | 200 | 200 | 94 | 167 | |
92 | 56.4 | 90.5 | 77.8 | 64.8 | 195 | 195 | 92 | 163 | |
91 | 55.8 | 90.2 | 77.1 | 63.8 | 190 | 190 | 90 | 160 | |
90 | 55.2 | 89.9 | 76.4 | 62.8 | 186 | 186 | 89 | 157 | |
89 | 54.6 | 89.5 | 76.8 | 61.8 | 180 | 180 | 88 | 164 | |
88 | 64.0 | 89.2 | 75.1 | 60.8 | 176 | 176 | 86 | 151 | |
87 | 53.4 | 88.9 | 74.4 | 59.8 | 172 | 172 | 84 | 148 | |
86 | 52.8 | 88.6 | 73.8 | 58.8 | 169 | 169 | 83 | 145 | |
85 | 52.3 | 88.2 | 73.1 | 57.8 | 165 | 165 | 82 | 142 | |
84 | 51.7 | 87.9 | 72.4 | 56.8 | 162 | 162 | 81 | 140 | |
83 | 51.1 | 87.6 | 71.8 | 55.8 | 159 | 159 | 80 | 137 | |
82 | 50.6 | 87.3 | 71.1 | 54.8 | 156 | 156 | 76 | 135 | |
81 | 50.0 | 86.9 | 70.4 | 53.8 | 153 | 153 | 73 | 133 | |
80 | 49.5 | 86.6 | 69.7 | 52.8 | 150 | 150 | 72 | 130 | |
79 | 48.9 | 86.3 | 69.1 | 51.8 | 147 | 147 | 70 | 128 | |
78 | 48.4 | 86.0 | 68.4 | 50.8 | 144 | 144 | 69 | 126 | |
77 | 47.9 | 85.6 | 67.7 | 49.8 | 141 | 141 | 68 | 124 | |
76 | 47.3 | 85.3 | 67.1 | 48.8 | 139 | 139 | 67 | 122 | |
75 | 46.8 | 86.0 | 66.4 | 47.8 | 137 | 137 | 66 | 120 | |
74 | 46.3 | 84.7 | 65.7 | 46.8 | 135 | 135 | 66 | 118 | |
73 | 45.8 | 84.3 | 65.1 | 45.8 | 132 | 132 | 64 | 116 | |
72 | 45.3 | 84.0 | 64.4 | 44.8 | 130 | 130 | 63 | 114 | |
71 | 44.8 | 100.0 | 83.7 | 63.7 | 43.8 | 127 | 127 | 62 | 112 |
70 | 44.3 | 99.5 | 83.4 | 63.1 | 42.8 | 125 | 125 | 61 | 110 |
69 | 43.8 | 99.0 | 83.0 | 62.4 | 41.8 | 123 | 123 | 60 | 109 |
68 | 43.3 | 98.0 | 82.7 | 61.7 | 40.8 | 121 | 121 | 59 | 108 |
67 | 42.8 | 97.5 | 82.4 | 61.0 | 39.8 | 119 | 119 | 58 | 106 |
66 | 42.3 | 97.0 | 82.1 | 60.4 | 38.7 | 117 | 117 | 57 | 104 |
65 | 41.8 | 96.0 | 81.8 | 59.7 | 37.7 | 116 | 116 | 56 | 102 |
64 | 41.4 | 95.5 | 81.4 | 59.0 | 36.7 | 114 | 114 | 100 | |
63 | 40.9 | 95.0 | 81.1 | 58.4 | 35.7 | 112 | 112 | 99 | |
62 | 40.4 | 94.5 | 80.8 | 57.7 | 34.7 | 110 | 110 | 98 | |
61 | 40.0 | 93.5 | 80.5 | 57.0 | 33.7 | 108 | 108 | 96 | |
60 | 39.5 | 93.0 | 80.1 | 56.4 | 32.7 | 107 | 107 | 95 | |
59 | 39.0 | 92.5 | 79.8 | 55.7 | 31.7 | 106 | 106 | 94 | |
58 | 38.6 | 92.0 | 79.5 | 55.0 | 30.7 | 104 | 104 | 92 | |
57 | 38.1 | 91.0 | 79.2 | 54.4 | 3.0 | 103 | 103 | 91 | |
56 | 37.7 | 90.6 | 78.8 | 53.7 | 28.7 | 101 | 101 | 90 | |
55 | 37.2 | 90.0 | 78.6 | 53.0 | 27.7 | 100 | 100 | 89 | |
54 | 36.8 | 89.5 | 78.2 | 52.4 | 26.7 | 87 | |||
53 | 36.3 | 89.0 | 77.9 | 51.7 | 26.7 | 86 | |||
52 | 35.9 | 88.0 | 77.5 | 51.0 | 24.7 | 85 | |||
51 | 35.5 | 87.6 | 77.2 | 50.3 | 23.7 | 84 | |||
50 | 35.0 | 87.0 | 76.9 | 49.7 | 22.7 | 83 | |||
49 | 34.6 | 86.5 | 76.6 | 49.0 | 21.7 | 82 | |||
48 | 34.1 | 85.5 | 76.2 | 48.3 | 20.7 | 81 | |||
47 | 33.7 | 85.0 | 75.9 | 47.7 | 19.7 | 80 | |||
46 | 33.3 | 84.6 | 76.6 | 47.0 | 18.7 | 80 | |||
45 | 32.9 | 84.0 | 76.3 | 46.3 | 17.7 | 79 | |||
44 | 32.4 | 83.5 | 74.9 | 45.7 | 16.7 | 78 | |||
43 | 32.0 | 82.5 | 74.6 | 45.0 | 15.7 | 77 | |||
42 | 31.6 | 82.0 | 74.3 | 44.3 | 14.7 | 76 | |||
41 | 31.2 | 81.5 | 74.0 | 43.7 | 13.6 | 75 | |||
40 | 30.7 | 81.0 | 73.6 | 43.0 | 12.6 | 75 | |||
39 | 30.3 | 80.0 | 73.3 | 42.3 | 11.6 | 74 | |||
38 | 29.9 | 79.5 | 73.0 | 41.6 | 10.6 | 73 | |||
37 | 29.5 | 79.0 | 72.7 | 41.0 | 9.6 | 72 | |||
36 | 29.1 | 78.5 | 72.3 | 40.3 | 8.6 | 72 | |||
35 | 28.7 | 78.0 | 72.0 | 39.6 | 7.6 | 71 | |||
34 | 28.2 | 77.0 | 71.7 | 39.0 | 6.6 | 70 | |||
33 | 27.8 | 76.6 | 71.4 | 38.3 | 5.6 | 69 | |||
32 | 27.4 | 76.0 | 71.0 | 37.6 | 4.6 | 69 | |||
31 | 27.0 | 75.5 | 70.7 | 37.0 | 3.6 | 68 | |||
30 | 26.6 | 75.0 | 70.4 | 36.3 | 2.6 | 67 |
Hardness values in brackets are outside the range recommended for Brinell testing in ASTM E-10. The above table is from ASTM E-110 except values for E-scale and Tensile Strength which are not from or according to ASTM Standards. Reprinted from the Annual Book of ASTM Standards, copyright American Society for Testing and Materials.