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Hardness Conversion Charts & Calculator  *

Comparison of Hardness Scales approx.** and Tensile Stress
Equivalents approx. (maximum value) in imperial and metric units.
Rockwell Vickers
Diamond Penetrator
Brinell Tensile Stress
Equivalents
Shore Scleroscope Rockwell Vickers
Diamond Penetrator
'C' Scale (HRC) Scale HV10 HV30 Dia. Imp. for
10mm Ball
Carbide Ball Standard Ball Tons/in2 1000lb/in2 kg/mm2 MPa
{N/mm2}
Hardness Number A Scale, 60-kgf (HRA) 'C' Scale (HRC) Scale HV10 HV30
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
HRB
                    Hardness
'B' Scale
HRB
 
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.


Hardness Conversion Chart
Rockwell Rockwell Superficial Brinell Vickers Shore  
A B C D E F 15-N 30-N 45-N 30-T 500 kg 3000 kg 136   Approx.
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 Sclero-scope Tensile Strength (psi)
86.5 - 70 78.5 - - 94 86 77.6 - - - 1076 101 -
86 - 69 77.7 - - 93.5 85 76.5 - - - 1044 99 -
85.6 - 68 76.9 - - 93.2 84.4 75.4 - - - 940 97 -
85 - 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 - - 739 832 91 -
83.4 - 64 73.8 - - 91.8 81.1 71 - - 722 800 88 -
82.8 - 63 73 - - 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 - 56 67.7 - - 88.3 73.9 62 - - 577 613 75 282,000
78.5 120 55 66.9 - - 87.9 73 60.9 - - 560 595 74 274,000
78 120 54 66.1 - - 87.4 72 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 - - 475 513 67 233,000
75.2 117 49 62.1 - - 85 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 - - 83.5 64.8 50.3 - - 432 458 62 212,000
73.1 115 45 59.2 - - 83 64 49 - - 421 446 60 206,000
72.5 114 44 58.5 - - 82.5 63.1 47.8 - - 409 434 58 200,000
72 113 43 57.7 - - 82 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 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 - - 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 50.4 31.3 - - 286 302 42 140,000
64.7 104 29 47 - - 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 24.3 - - 247 260 37 121,000
62 100 23 42.1 - - 71 44 23.1 82 201 240 254 36 118,000
61.5 99 22 41.6 - - 70.5 43.2 22 81.5 195 234 248 35 115,000
61 98 21 40.9 - - 69.9 42.3 20.7 81 189 228 243 35 112,000
60.5 97 20 40.1 - - 69.4 41.5 19.6 80.5 184 222 238 34 109,000
59 96 18 - - - - - - 80 179 216 230 33 106,000
58 95 16 - - - - - - 79 175 210 222 32 103,000
57.5 94 15 - - - - - - 78.5 171 205 213 31 100,000
57 93 13 - - - - - - 78 167 200 208 30 98,000
56.5 92 12 - - - - - - 77.5 163 195 204 29 96,000
56 91 10 - - - - - - 77 160 190 196 28 93,000
55.5 90 9 - - - - - - 76 157 185 192 27 91,000
55 89 8 - - - - - - 75.5 154 180 188 26 88,000
54 88 7 - - - - - - 75 151 176 184 26 86,000
53.5 87 6 - - - - - - 74.5 148 172 180 26 84,000
53 86 5 - - - - - - 74 145 169 176 25 83,000
52.5 85 4 - - - - - - 73.5 142 165 173 25 81,000
52 84 3 - - - - - - 73 140 162 170 25 79,000
51 83 2 - - - - - - 72 137 159 166 24 78,000
50.5 82 1 - - - - - - 71.5 135 156 163 24 76,000
50 81 0 - - - - - - 71 133 153 160 24 75,000
49.5 80 - - - - - - - 70 130 150 - - 73,000
49 79 - - - - - - - 69.5 128 147 - - -
48.5 78 - - - - - - - 69 126 144 - - -
48 77 - - - - - - - 68 124 141 - - -
47 76 - - - - - - - 67.5 122 139 - - -
46.5 75 - - - 99.5 - - - 67 120 137 - - -
46 74 - - - 99 - - - 66 118 135 - - -
45.5 73 - - - 98.5 - - - 65.5 116 132 - - -
45 72 - - - 98 - - - 65 114 130 - - -
44.5 71 - - 100 97.5 - - - 64.2 112 127 - - -
44 70 - - 99.5 97 - - - 63.5 110 125 - - -
43.5 69 - - 99 96 - - - 62.8 109 123 - - -
43 68 - - 98 95.5 - - - 62 107 121 - - -
42.5 67 - - 97.5 95 - - - 61.4 106 119 - - -
42 66 - - 97 94.5 - - - 60.5 104 117 - - -
41.8 65 - - 96 94 - - - 60.1 102 116 - - -
41.5 64 - - 95.5 93.5 - - - 59.5 101 114 - - -
41 63 - - 95 93 - - - 58.7 99 112 - - -
40.5 62 - - 94.5 92 - - - 58 98 110 - - -
40 61 - - 93.5 91.5 - - - 57.3 96 108 - - -
39.5 60 - - 93 91 - - - 56.5 95 107 - - -
39 59 - - 92.5 90.5 - - - 55.9 94 106 - - -
38.5 58 - - 92 90 - - - 55 92 104 - - -
38 57 - - 91 89.5 - - - 54.6 91 102 - - -
37.8 56 - - 90.5 89 - - - 54 90 101 - - -
37.5 55 - - 90 88 - - - 53.2 89 99 - - -
37 54 - - 89.5 87.5 - - - 52.5 87 - - - -
36.5 53 - - 89 87 - - - 51.8 86 - - - -
36 52 - - 88 86.5 - - - 51 85 - - - -
35.5 51 - - 87.5 86 - - - 50.4 84 - - - -
35 50 - - 87 85.5 - - - 49.5 83 - - - -
34.8 49 - - 86.5 85 - - - 49.1 82 - - - -
34.5 48 - - 85.5 84.5 - - - 48.5 81 - - - -
34 47 - - 85 84 - - - 47.7 80 - - - -
33.5 46 - - 84.5 83 - - - 47 79 - - - -
33 45 - - 84 82.5 - - - 46.2 79 - - - -
32.5 44 - - 83.5 82 - - - 45.5 78 - - - -
32 43 - - 82.5 81.5 - - - 44.8 77 - - - -
31.5 42 - - 82 81 - - - 44 76 - - - -
31 41 - - 81.5 80.5 - - - 43.4 75 - - - -
30.8 40 - - 81 79.5 - - - 43 74 - - - -
30.5 39 - - 80 79 - - - 42.1 74 - - - -
30 38 - - 79.5 78.5 - - - 41.5 73 - - - -
29.5 37 - - 79 78 - - - 40.7 72 - - - -
29 36 - - 78.5 77.5 - - - 40 71 - - - -
28.5 35 - - 78 77 - - - 39.3 71 - - - -
28 34 - - 77 76.5 - - - 38.5 70 - - - -
27.8 33 - - 76.5 75.5 - - - 37.9 69 - - - -
27.5 32 - - 76 75 - - - 37.5 68 - - - -
27 31 - - 75.5 74.5 - - - 36.6 68 - - - -
26.5 30 - - 75 74 - - - 36 67 - - - -
26 29 - - 74 73.5 - - - 35.2 66 - - - -
25.5 28 - - 73.5 73 - - - 34.5 66 - - - -
25 27 - - 73 72.5 - - - 33.8 65 - - - -
24.5 26 - - 72.5 72 - - - 33.1 65 - - - -
24.2 25 - - 72 71 - - - 32.4 64 - - - -
24 24 - - 71 70.5 - - - 32 64 - - - -
23.5 23 - - 70.5 70 - - - 31.1 63 - - - -
23 22 - - 70 69.5 - - - 30.4 63 - - - -
22.5 21 - - 69.5 69 - - - 29.7 62 - - - -
22 20 - - 68.5 68.5 - - - 29 62 - - - -
21.5 19 - - 68 68 - - - 28.1 61 - - - -
21.2 18 - - 67.5 67 - - - 27.4 61 - - - -
21 17 - - 67 66.5 - - - 26.7 60 - - - -
20.5 16 - - 66.5 66 - - - 26 60 - - - -
20 15 - - 65.5 65.5 - - - 25.3 59 - - - -
- 14 - - 65 65 - - - 24.6 59 - - - -
- 13 - - 64.5 64.5 - - - 23.9 58 - - - -
- 12 - - 64 64 - - - 23.5 58 - - - -
- 11 - - 63.5 63.5 - - - 22.6 57 - - - -
- 10 - - 62.5 63 - - - 21.9 57 - - - -
- 9 - - 62 62 - - - 21.2 56 - - - -
- 8 - - 61.5 61.5 - - - 20.5 56 - - - -
- 7 - - 61 61 - - - 19.8 56 - - - -
- 6 - - 60.5 60.5 - - - 19.1 55 - - - -
- 5 - - 60 60 - - - 18.4 55 - - - -
- 4 - - 59 59.5 - - - 18 55 - - - -
- 3 - - 58.5 59 - - - 17.1 54 - - - -
- 2 - - 58 58 - - - 16.4 54 - - - -
- 1 - - 57.5 57.5 - - - 15.7 53 - - - -
- 0 - - 57 57 - - - 15 53 - - - -

Click for the ASTM E140 - 07 document: Standard Hardness Conversion Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rockwell Hardness, Superficial Hardness, Knoop Hardness, and Scleroscope Hardness

Hardness

Hardness is the property of a material that enables it to resist plastic deformation, penetration, indentation, and scratching. Therefore, hardness is important from an engineering standpoint because resistance to wear by either friction or erosion by steam, oil, and water generally increases with hardness.

Hardness tests serve an important need in industry even though they do not measure a unique quality that can be termed hardness. The tests are empirical, based on experiments and observation, rather than fundamental theory. Its chief value is as an inspection device, able to detect certain differences in material when they arise even though these differences may be undefinable. For example, two lots of material that have the same hardness may or may not be alike, but if their hardness is different, the materials certainly are not alike.

Several methods have been developed for hardness testing. Those most often used are Brinell, Rockwell, Vickers, Tukon, Sclerscope, and the files test. The first four are based on indentation tests and the fifth on the rebound height of a diamond-tipped metallic hammer. The file test establishes the characteristics of how well a file takes a bite on the material.

As a result of many tests, comparisons have been prepared using formulas, tables, and graphs that show the relationships between the results of various hardness tests of specific alloys. There is, however, no exact mathematical relation between any two of the methods. For this reason, the result of one type of hardness test converted to readings of another type should carry the notation "____ converted from ____" (for example "352 Brinell converted from Rockwell C-38").

Another convenient conversion is that of Brinell hardness to ultimate tensile strength. For quenched and tempered steel, the tensile strength (psi) is about 500 times the Brinell hardness number (provided the strength is not over 200,000 psi).

 Hardness conversion calculator: astm E 140 - 97

 

 from 
 to
1) Standard Hardness Conversion for metals acc. ASTM E 140 - 97, September 1999, Conversion for Non-Austenitic Steels, Table 1. The accuracy of the conversion depends on the accuracy of the provided data and the resulting curve-fits.
2) Indentation hardness is not a single fundamental property but a combination of properties, and varies with the type of test. The modulus of elasticity and the depth of indentation influence conversions. Therefore separate conversion tables are neccessary for different materials.
3) Brinell Hardness numbers in parentheses are outsite the range (HB>630) This limit is set to avoid errors introduced by the deformation of the ball indenter itself.
This Hardness conversion calculator is ©  www.tribology-abc.com

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