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Approximate Conversion Values for Rockwell C Hardness of Steel Materials

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Rockwell C scale hardness
(HRC)
Vickers hardness
(HV)
Brinell hardness (HB) 10 mm ball 3000 kgf load Rockwell hardness Rockwell superficial hardness diamond conical indenter Shore hardness
(HS)
Tensile strength [MPa] (approximate value)

1MPa=
1N/mm 2
Rockwell C scale hardness (HRC)
Standard ball Tungsten carbide ball A scale (HRA) 60 kgf load diamond conical indenter B scale (HRB) 100 kgf load 1.6 mm diameter (1/16 in) ball D scale (HRD) 100 kgf load diamond conical indenter 15 - N scale 15 kgf load 30 - N scale 30 kgf load 45 - N scale 45 kgf load
68 940 85.6 76.9 93.2 84.4 75.4 97 68
67 900 85.0 76.1 92.9 83.6 74.2 95 67
66 865 84.5 75.4 92.5 82.8 73.3 92 66
65 832 (739) 83.9 74.5 92.2 81.9 72.0 91 65
64 800 (722) 83.4 73.8 91.8 81.1 71.0 88 64
                         
63 772 (705) 82.8 73.0 91.4 80.1 69.9 87 63
62 746 (688) 82.3 72.2 91.1 79.3 68.8 85 62
61 720 (670) 81.8 71.5 90.7 78.4 67.7 83 61
60 697 (654) 81.2 70.7 90.2 77.5 66.6 81 60
59 674 (634) 80.7 69.9 89.8 56.6 65.5 80 59
                         
58 653 615 80.1 69.2 89.3 75.7 64.3 78 58
57 633 595 79.6 68.5 88.9 74.8 63.2 76 57
56 613 577 79.0 67.7 88.3 73.9 62.0 75 56
55 595 560 78.5 66.9 87.9 73.0 60.9 74 2075 55
54 577 543 78.0 66.1 87.4 72.0 59.8 72 2015 54
                         
53 560 525 77.4 65.4 86.9 71.2 58.5 71 1950 53
52 544 (500) 512 76.8 64.6 86.4 70.2 57.4 69 1880 52
51 528 (487) 496 76.3 63.8 85.9 69.4 56.1 68 1820 51
50 513 (475) 481 75.9 63.1 85.5 68.5 55.0 67 1760 50
49 498 (464) 469 75.2 62.1 85.0 67.6 53.8 66 1695 49
                         
48 484 451 455 74.7 61.4 84.5 66.7 52.5 64 1635 48
47 471 442 443 74.1 60.8 83.9 65.8 51.4 63 1580 47
46 458 432 432 73.6 60.0 83.5 64.8 50.3 62 1530 46
45 446 421 421 73.1 59.2 83.0 64.0 49.0 60 1480 45
44 434 409 409 72.5 58.5 82.5 63.1 47.8 58 1435 44
                         
43 423 400 400 72.0 57.7 82.0 62.2 46.7 57 1385 43
42 412 390 390 71.5 56.9 81.5 61.3 45.5 56 1340 42
41 402 381 381 70.9 56.2 80.9 60.4 44.3 55 1295 41
40 392 371 371 70.4 55.4 80.4 59.5 43.1 54 1250 40
39 382 362 362 69.9 54.6 79.9 58.6 41.9 52 1215 39
                         
38 372 353 353 69.4 53.8 79.4 57.7 40.8 51 1180 38
37 363 344 344 68.9 53.1 78.8 56.8 39.6 50 1160 37
36 354 336 336 68.4 (109.0) 52.3 78.3 55.9 38.4 49 1115 36
35 345 327 327 67.9 (108.5) 51.5 77.7 55.0 37.2 48 1080 35
34 336 319 319 67.4 (108.0) 50.8 77.2 54.2 36.1 47 1055 34
                         
33 327 311 311 66.8 (107.5) 50.0 76.6 53.3 34.9 46 1025 33
32 318 301 301 66.3 (107.0) 49.2 76.1 52.1 33.7 44 1000 32
31 310 294 294 65.8 (106.0) 48.4 75.6 51.3 32.7 43 980 31
30 302 286 286 65.3 (105.5) 47.7 75.0 50.4 31.3 42 950 30
29 294 279 279 64.7 (104.5) 47.0 74.5 49.5 30.1 41 930 29
                         
28 286 271 271 64.3 (104.0) 46.1 73.9 48.6 28.9 41 910 28
27 279 264 264 63.8 (103.0) 45.2 73.3 47.7 27.8 40 880 27
26 272 258 258 63.3 (102.5) 44.6 72.8 46.8 26.7 38 860 26
25 266 253 253 62.8 (101.5) 43.8 72.2 45.9 25.5 38 840 25
24 260 247 247 62.4 (101.0) 43.1 71.6 45.0 24.3 37 825 24
                         
23 254 243 243 62.0 100.0 42.1 71.0 44.0 23.1 36 805 23
22 248 237 237 61.5 99.0 41.6 70.5 43.2 22.0 35 785 22
21 243 231 231 61.0 98.5 40.9 69.9 42.3 20.7 35 770 21
20 238 226 226 60.5 97.8 40.1 69.4 41.5 19.6 34 760 20
(18) 230 219 219 96.7 33 730 (18)
* The bold numbers are based on the ASTM E-140 table (adjusted by SAE, ASM, and ASTM in collaboration).
* The numbers in parentheses in the table are not used very much and are shown as a reference.

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