Hardness Conversion Chart

Hardness Conversion Chart
 
Rockwell Rockwell Superficial Brinell Vickers Shore  
A B C D E F 15-N 30-N 45-N 30-T 3000 kg 500 kg 136

 

Approx Tensile Strength (psi)
60kg Brale 100kg 1/16" Ball 150kg Brale 100kg Brale 100kg 1/8" Ball 60kg 1/16" Ball 15kg Brale 30kg Brale 45kg Brale 30 kg 1/16" Ball 10mm Ball Steel 10mm Ball Steel Diamond Pyramid Sciero-scope
86.5 --- 70 78.5 --- --- 94.0 86.0 77.6 --- --- --- 1076 101 ---
86.0 --- 69 77.7 --- --- 93.5 85.0 76.5 --- --- --- 1044 99 ---
85.6 --- 68 76.9 --- --- 93.2 84.4 75.4 --- --- --- 940 97 ---
85.0 --- 67 76.1 --- --- 92.9 83.6 74.2 --- --- --- 900 95 ---
84.5 --- 66 75.4 --- --- 92.5 82.8 73.2 --- --- --- 865 92 ---
83.9 --- 65 74.5 --- --- 92.2 81.9 72.0 --- 739 --- 832 91 ---
83.4 --- 64 73.8 --- --- 91.8 81.1 71.0 --- 722 --- 800 88 ---
82.8 --- 63 73.0 --- --- 91.4 80.1 69.9 --- 705 --- 772 87 ---
82.3 --- 62 72.2 --- --- 91.1 79.3 68.8 --- 688 --- 746 85 ---
81.8 --- 61 71.5 --- --- 90.7 78.4 67.7 --- 670 --- 720 83 ---
81.2 --- 60 70.7 --- --- 90.2 77.5 66.6 --- 654 --- 697 81 320,000
80.7 --- 59 69.9 --- --- 89.8 76.6 65.5 --- 634 --- 674 80 310,000
80.1 --- 58 69.2 --- --- 89.3 75.7 64.3 --- 615 --- 653 78 300,000
79.6 --- 57 68.5 --- --- 88.9 74.8 63.2 --- 595 --- 633 76 290,000
79.0 --- 56 67.7 --- --- 88.3 73.9 62.0 --- 577 --- 613 75 282,000
78.5 120 55 66.9 --- --- 87.9 73.0 60.9 --- 560 --- 595 74 274,000
78.0 120 54 66.1 --- --- 87.4 72.0 59.8 --- 543 --- 577 72 266,000
77.4 119 53 65.4 --- --- 86.9 71.2 58.6 --- 525 --- 560 71 257,000
76.8 119 52 64.6 --- --- 86.4 70.2 57.4 --- 500 --- 544 69 245,000
76.3 118 51 63.8 --- --- 85.9 69.4 56.1 --- 487 --- 528 68 239,000
75.9 117 50 63.1 --- --- 85.5 68.5 55.0 --- 475 --- 513 67 233,000
75.2 117 49 62.1 --- --- 85.0 67.6 53.8 --- 464 --- 498 66 227,000
74.7 116 48 61.4 --- --- 84.5 66.7 52.5 --- 451 --- 484 64 221,000
74.1 116 47 60.8 --- --- 83.9 65.8 51.4 --- 442 --- 471 63 217,000
73.6 115 46 60.0 --- --- 83.5 64.8 50.3 --- 432 --- 458 62 212,000
73.1 115 45 59.2 --- --- 83.0 64.0 49.0 --- 421 --- 446 60 206,000
72.5 114 44 58.5 --- --- 82.5 63.1 47.8 --- 409 --- 434 58 200,000
72.0 113 43 57.7 --- --- 82.0 62.2 46.7 --- 400 --- 423 57 196,000
71.5 113 42 56.9 --- --- 81.5 61.3 45.5 --- 390 --- 412 56 191,000
70.9 112 41 56.2 --- --- 80.9 60.4 44.3 --- 381 --- 402 55 187,000
70.4 112 40 55.4 --- --- 80.4 59.5 43.1 --- 371 --- 392 54 182,000
69.9 111 39 54.6 --- --- 79.9 58.6 41.9 --- 362 --- 382 52 177,000
69.4 110 38 53.8 --- --- 79.4 57.7 40.8 --- 353 --- 372 51 173,000
68.9 110 37 53.1 --- --- 78.8 56.8 39.6 --- 344 --- 363 50 169,000
68.4 109 36 52.3 --- --- 78.3 55.9 38.4 --- 336 --- 354 49 165,000
67.9 109 35 51.5 --- --- 77.7 55.0 37.2 --- 327 --- 345 48 160,000
67.4 108 34 50.8 --- --- 77.2 54.2 36.1 --- 319 --- 336 47 156,000
66.8 108 33 50.0 --- --- 76.6 53.3 34.9 --- 311 --- 327 46 152,000
66.3 107 32 49.2 --- --- 76.1 52.1 33.7 --- 301 --- 318 44 147,000
65.8 106 31 48.4 --- --- 75.6 51.3 32.5 --- 294 --- 310 43 144,000
65.3 105 30 47.7 --- --- 75.0 50.4 31.3 --- 286 --- 302 42 140,000
64.7 104 29 47.0 --- --- 74.5 49.5 30.1 --- 279 --- 294 41 137,000
64.3 104 28 46.1 --- --- 73.9 48.6 28.9 --- 271 --- 286 41 133,000
63.8 103 27 45.2 --- --- 73.3 47.7 27.8 --- 264 --- 279 40 129,000
63.3 103 26 44.6 --- --- 72.8 46.8 26.7 --- 258 --- 272 39 126,000
62.8 102 25 43.8 --- --- 72.2 45.9 25.5 --- 253 --- 266 38 124,000
62.4 101 24 43.1 --- --- 71.6 45.0 24.3 --- 247 --- 260 37 121,000
62.0 100 23 42.1 --- --- 71.0 44.0 23.1 82.0 240 201 254 36 118,000
61.5 99 22 41.6 --- --- 70.5 43.2 22.0 81.5 234 195 248 35 115,000
61.0 98 21 40.9 --- --- 69.9 42.3 20.7 81.0 228 189 243 35 112,000
60.5 97 20 40.1 --- --- 69.4 41.5 19.6 80.5 222 184 238 34 109,000
59.0 96 18 --- --- --- --- --- --- 80.0 216 179 230 33 106,000
58.0 95 16 --- --- --- --- --- --- 79.0 210 175 222 32 103,000
57.5 94 15 --- --- --- --- --- --- 78.5 205 171 213 31 100,000
57.0 93 13 --- --- --- --- --- --- 78.0 200 167 208 30 98,000
56.5 92 12 --- --- --- --- --- --- 77.5 195 163 204 29 96,000
56.0 91 10 --- --- --- --- --- --- 77.0 190 160 196 28 93,000
55.5 90 9 --- --- --- --- --- --- 76.0 185 157 192 27 91,000
55.0 89 8 --- --- --- --- --- --- 75.5 180 154 188 26 88,000
54.0 88 7 --- --- --- --- --- --- 75.0 176 151 184 26 86,000
53.5 87 6 --- --- --- --- --- --- 74.5 172 148 180 26 84,000
53.0 86 5 --- --- --- --- --- --- 74.0 169 145 176 25 83,000
52.5 85 4 --- --- --- --- --- --- 73.5 165 142 173 25 81,000
52.0 84 3 --- --- --- --- --- --- 73.0 162 140 170 25 79,000
51.0 83 2 --- --- --- --- --- --- 72.0 159 137 166 24 78,000
50.5 82 1 --- --- --- --- --- --- 71.5 156 135 163 24 76,000
50.0 81 0 --- --- --- --- --- --- 71.0 153 133 160 24 75,000
49.5 80 --- --- --- --- --- --- --- 70.0 150 130 --- --- 73,000
49.0 79 --- --- --- --- --- --- --- 69.5 147 128 --- --- ---
48.5 78 --- --- --- --- --- --- --- 69.0 144 126 --- --- ---
48.0 77 --- --- --- --- --- --- --- 68.0 141 124 --- --- ---
47.0 76 --- --- --- --- --- --- --- 67.5 139 122 --- --- ---
46.5 75 --- --- --- 99.5 --- --- --- 67.0 137 120 --- --- ---
46.0 74 --- --- --- 99.0 --- --- --- 66.0 135 118 --- --- ---
45.5 73 --- --- --- 98.5 --- --- --- 65.5 132 116 --- --- ---
45.0 72 --- --- --- 98.0 --- --- --- 65.0 130 114 --- --- ---
44.5 71 --- --- 100.0 97.5 --- --- --- 64.2 127 112 --- --- ---
44.0 70 --- --- 99.5 97.0 --- --- --- 63.5 125 110 --- --- ---
43.5 69 --- --- 99.0 96.0 --- --- --- 62.8 123 109 --- --- ---
43.0 68 --- --- 98.0 95.5 --- --- --- 62.0 121 107 --- --- ---
42.5 67 --- --- 97.5 95.0 --- --- --- 61.4 119 106 --- --- ---
42.0 66 --- --- 97.0 94.5 --- --- --- 60.5 117 104 --- --- ---
41.8 65 --- --- 96.0 94.0 --- --- --- 60.1 116 102 --- --- ---
41.5 64 --- --- 95.5 93.5 --- --- --- 59.5 114 101 --- --- ---
41.0 63 --- --- 95.0 93.0 --- --- --- 58.7 112 99 --- --- ---
40.5 62 --- --- 94.5 92.0 --- --- --- 58.0 110 98 --- --- ---
40.0 61 --- --- 93.5 91.5 --- --- --- 57.3 108 96 --- --- ---
39.5 60 --- --- 93.0 91.0 --- --- --- 56.5 107 95 --- --- ---
39.0 59 --- --- 92.5 90.5 --- --- --- 55.9 106 94 --- --- ---
38.5 58 --- --- 92.0 90.0 --- --- --- 55.0 104 92 --- --- ---
38.0 57 --- --- 91.0 89.5 --- --- --- 54.6 102 91 --- --- ---
37.8 56 --- --- 90.5 89.0 --- --- --- 54.0 101 90 --- --- ---
37.5 55 --- --- 90.0 88.0 --- --- --- 53.2 99 89 --- --- ---
37.0 54 --- --- 89.5 87.5 --- --- --- 52.5 --- 87 --- --- ---
36.5 53 --- --- 89.0 87.0 --- --- --- 51.8 --- 86 --- --- ---
36.0 52 --- --- 88.0 86.5 --- --- --- 51.0 --- 85 --- --- ---
35.5 51 --- --- 87.5 86.0 --- --- --- 50.4 --- 84 --- --- ---
35.0 50 --- --- 87.0 85.5 --- --- --- 49.5 --- 83 --- --- ---
34.8 49 --- --- 86.5 85.0 --- --- --- 49.1 --- 82 --- --- ---
34.5 48 --- --- 85.5 84.5 --- --- --- 48.5 --- 81 --- --- ---
34.0 47 --- --- 85.0 84.0 --- --- --- 47.7 --- 80 --- --- ---
33.5 46 --- --- 84.5 83.0 --- --- --- 47.0 --- 79 --- --- ---
33.0 45 --- --- 84.0 82.5 --- --- --- 46.2 --- 79 --- --- ---
32.5 44 --- --- 83.5 82.0 --- --- --- 45.5 --- 78 --- --- ---
32.0 43 --- --- 82.5 81.5 --- --- --- 44.8 --- 77 --- --- ---
31.5 42 --- --- 82.0 81.0 --- --- --- 44.0 --- 76 --- --- ---
31.0 41 --- --- 81.5 80.5 --- --- --- 43.4 --- 75 --- --- ---
30.8 40 --- --- 81.0 79.5 --- --- --- 43.0 --- 74 --- --- ---
30.5 39 --- --- 80.0 79.0 --- --- --- 42.1 --- 74 --- --- ---
30.0 38 --- --- 79.5 78.5 --- --- --- 41.5 --- 73 --- --- ---
29.5 37 --- --- 79.0 78.0 --- --- --- 40.7 --- 72 --- --- ---
29.0 36 --- --- 78.5 77.5 --- --- --- 40.0 --- 71 --- --- ---
28.5 35 --- --- 78.0 77.0 --- --- --- 39.3 --- 71 --- --- ---
28.0 34 --- --- 77.0 76.5 --- --- --- 38.5 --- 70 --- --- ---
27.8 33 --- --- 76.5 75.5 --- --- --- 37.9 --- 69 --- --- ---
27.5 32 --- --- 76.0 75.0 --- --- --- 37.5 --- 68 --- --- ---
27.0 31 --- --- 75.5 74.5 --- --- --- 36.6 --- 68 --- --- ---
26.5 30 --- --- 75.0 74.0 --- --- --- 36.0 --- 67 --- --- ---
26.0 29 --- --- 74.0 73.5 --- --- --- 35.2 --- 66 --- --- ---
25.5 28 --- --- 73.5 73.0 --- --- --- 34.5 --- 66 --- --- ---
25.0 27 --- --- 73.0 72.5 --- --- --- 33.8 --- 65 --- --- ---
24.5 26 --- --- 72.5 72.0 --- --- --- 33.1 --- 65 --- --- ---
24.2 25 --- --- 72.0 71.0 --- --- --- 32.4 --- 64 --- --- ---
24.0 24 --- --- 71.0 70.5 --- --- --- 32.0 --- 64 --- --- ---
23.5 23 --- --- 70.5 70.0 --- --- --- 31.1 --- 63 --- --- ---
23.0 22 --- --- 70.0 69.5 --- --- --- 30.4 --- 63 --- --- ---
22.5 21 --- --- 69.5 69.0 --- --- --- 29.7 --- 62 --- --- ---
22.0 20 --- --- 68.5 68.5 --- --- --- 29.0 --- 62 --- --- ---
21.5 19 --- --- 68.0 68.0 --- --- --- 28.1 --- 61 --- --- ---
21.2 18 --- --- 67.5 67.0 --- --- --- 27.4 --- 61 --- --- ---
21.0 17 --- --- 67.0 66.5 --- --- --- 26.7 --- 60 --- --- ---
20.5 16 --- --- 66.5 66.0 --- --- --- 26.0 --- 60 --- --- ---
20.0 15 --- --- 65.5 65.5 --- --- --- 25.3 --- 59 --- --- ---
--- 14 --- --- 65.0 65.0 --- --- --- 24.6 --- 59 --- --- ---
--- 13 --- --- 64.5 64.5 --- --- --- 23.9 --- 58 --- --- ---
--- 12 --- --- 64.0 64.0 --- --- --- 23.5 --- 58 --- --- ---
--- 11 --- --- 63.5 63.5 --- --- --- 22.6 --- 57 --- --- ---
--- 10 --- --- 62.5 63.0 --- --- --- 21.9 --- 57 --- --- ---
--- 9 --- --- 62.0 62.0 --- --- --- 21.2 --- 56 --- --- ---
--- 8 --- --- 61.5 61.5 --- --- --- 20.5 --- 56 --- --- ---
--- 7 --- --- 61.0 61.0 --- --- --- 19.8 --- 56 --- --- ---
--- 6 --- --- 60.5 60.5 --- --- --- 19.1 --- 55 --- --- ---
--- 5 --- --- 60.0 60.0 --- --- --- 18.4 --- 55 --- --- ---
--- 4 --- --- 59.0 59.5 --- --- --- 18.0 --- 55 --- --- ---
--- 3 --- --- 58.5 59.0 --- --- --- 17.1 --- 54 --- --- ---
--- 2 --- --- 58.0 58.0 --- --- --- 16.4 --- 54 --- --- ---
--- 1 --- --- 57.5 57.5 --- --- --- 15.7 --- 53 --- --- ---
--- 0 --- --- 57.0 57.0 --- --- --- 15.0 --- 53 --- --- ---

Comparison of Hardness Scales approx.** and Tensile Stress
Equivalents approx. (maximum value) in imperial and metric units.

Rockwell 'C' Scale Diamond Pyramid Scale 
HV10 HV30
Brinell Tensile Stress 
Equivalents
Scler Scope 
Hardness Number
Rockwell Diamond Pyramid 
Scale HV10 HV30
    Dia. Imp. for 
10mm Ball
Carbide Ball Standard Ball Tons/in2 1000lb/in2 kg/mm2 MPa
{N/mm2}
       
67.7 900               96 85.6 67.7 900
67.0 880               95 85.0 67.0 880
66.3 860               93 84.7 66.3 860
65.5 840               92 84.2 65.5 840
64.8 820               90 83.8 64.8 820
64.0 800               88 83.4 64.0 800
63.3 780               87 83.0 63.3 780
62.5 760               86 82.6 62.5 760
61.7 740               84 82.2 61.7 740
61.0 725 2.44 630 - - - - - 82 81.8 61.0 725
60.5 710 2.45 627 - - - - - - 81.5 60.5 710
60.0 698 2.50 601 - 132 295 208 2039 81 81.2 60.0 698
58.9 670 2.55 578 - 127 284 200 1961 78 80.6 58.9 670
57.1 630 2.60 555 - 122 273 192 1884 75 79.6 57.1 630
56.1 609 2.65 534 - 117 262 184 1807 73 79.0 56.1 609
54.4 572 2.70 514 - 112 250 176 1729 71 78.2 54.4 572
51.9 532 2.75 495 495 108 241 170 1668 68 76.9 51.9 532
50.7 517 2.80 477 477 105 235 165 1621 66 76.3 50.7 517
49.5 497 2.85 461 461 101 226 160 1559 64 75.5 49.5 497
47.5 470 2.90 444 444 98 219 155 1513 62 74.2 47.5 470
46.0 452 2.95 429 429 95 212 150 1467 60 73.5 46.0 452
44.8 437 3.00 415 415 92 206 145 1420 58 73.0 44.8 437
43.7 422 3.05 401 401 88 197 139 1359 56 72.5 43.7 422
42.4 408 3.10 388 388 85 190 134 1312 54 71.5 42.4 408
41.3 395 3.15 375 375 82 183 129 1266 52 71.0 41.3 395
39.9 381 3.20 363 363 80 179 126 1235 51 70.3 39.9 381
38.8 370 3.25 352 352 77 172 121 1189 49 69.8 38.8 370
37.7 359 3.30 341 341 75 168 118 1158 48 69.2 37.7 359
36.7 349 3.35 331 331 73 163 114 1127 46 68.8 36.7 349
35.0 337 3.40 321 321 71 159 111 1096 45 68.0 35.0 337
34.0 327 3.45 311 311 68 152 107 1050 43 67.5 34.0 327
33.0 318 3.50 302 302 66 147 104 1019 42 66.8 33.0 318
32.0 308 3.55 293 293 64 143 101 988 41 66.2 32.0 308
30.9 300 3.60 285 285 63 141 99 973 40 65.7 30.9 300
29.8 292 3.65 277 277 61 136 96 942 38 65.2 29.8 292
29.0 284 3.70 269 269 59 132 93 911 37 64.6 29.0 284
27.5 275 3.75 262 262 58 130 91 895 36 64.0 27.5 275
26.6 269 3.80 255 255 56 125 89 865 35 63.6 26.6 269
25.2 261 3.85 248 248 55 123 87 849 34 62.9 25.2 261
24.3 255 3.90 241 241 53 118 84 818 33 62.6 24.3 255
23.0 247 3.95 235 235 51 114 81 787 32 62.0 23.0 247
22.0 241 4.00 229 229 50 112 79 772 31 61.6 22.0 241
20.8 234 4.05 223 223 49 110 77 756 30 60.7 20.8 234
  228 4.10 217 217 48 107 76 741 - - - 228
Hardness
'B' Scale
                    Hardness
'B' Scale
 
98 222 4.15 212 212 46 103 73 710 29 - 98 222
97 218 4.20 207 207 45 101 71 695 28 - 97 218
96 212 4.30 197 197 43 97 68 664 27 - 96 212
93 196 4.40 187 187 41 92 65 632 25 - 93 196
91 188 4.50 179 179 39 88 62 602 - - 91 188
88.5 178 4.60 170 170 36 81 57 556 24 - 88.5 178
86 171 4.70 163 163 35 78 55 540 - - 86 171
84.2 163 4.80 156 156 34 76 54 525 23 - 84.2 163
82 156 4.90 149 149 32 72 51 494 - - 82 156
80 150 5.00 143 143 3t 69 49 479 22 - 80 150
77 143 5.10 137 137 30 67 48 463 21 - 77 143
75 137 5.20 131 131 29.5 66 47 455 20.5 - 75 137
72.5 132 5.30 126 126 29 65 46 448 20 - 72.5 132
70 127 5.40 121 121 28 63 44 432 - - 70 127
67 122 5.50 116 116 26 58 42 401 15 - 67 122

*These charts were prepared using information contained in B.S.860/1967. This standard differs significantly from the superseded standard B.S. 860/1939, and differs slightly from the conversion scales adopted by SAE and ASTM sources.

** Where hardness acceptance values are specified and a conversion from one scale to another is necessary the source of the conversion data should be stated and understood by the parties involved.