A hardness conversion chart is a reference tool used in materials science and engineering to correlate the hardness values obtained from different hardness testing methods. Hardness is a measure of a material’s resistance to deformation, typically by indentation. Various testing methods are employed to determine hardness, each yielding values in different scales.
| TABLE 2A Approximate Hardness Conversion Numbers for Nonaustenitic Steels | ||||||||
|---|---|---|---|---|---|---|---|---|
| (Rockwell C to other Hardness Numbers) | ||||||||
| Rockwell Superficial Hardness | ||||||||
| Rockwell C Scale, 150-kgf Load, Diamond Penetrator | Vickers Hardness Number | Brinell Hardness, 3000-kgf Load, 10-mm Ball | Knoop Hardness, 500-gf Load and Over | Rockwell A Scale, 60-kgf Load, Diamond Penetrator | 15N Scale, 15-kgf Load, Diamond Penetrator | 30N Scale 30-kgf Load, Diamond Penetrator | 45N Scale, 45-kgf Load, Diamond Penetrator | Approximate Tensile Strength, ksi (MPa) |
| 48 | 484 | 455 | 510 | 74.7 | 84.5 | 66.7 | 52.5 | 238(1640) |
| 47 | 471 | 442 | 495 | 74.1 | 83.9 | 65.8 | 51.4 | 229(1580) |
| 46 | 458 | 432 | 480 | 73.8 | 83.5 | 64.8 | 50.3 | 221(1520) |
| 45 | 446 | 421 | 466 | 73.1 | 83 | 64 | 49 | 215(1480) |
| 44 | 434 | 409 | 452 | 72.5 | 82.5 | 63.1 | 47.8 | 208(1430) |
| 43 | 423 | 400 | 438 | 72 | 82 | 62.2 | 46.7 | 201(1390) |
| 42 | 412 | 390 | 426 | 71.5 | 81.5 | 61.3 | 45.5 | 194(1340) |
| 41 | 402 | 381 | 414 | 70.9 | 80.9 | 60.4 | 44.3 | 188(1300) |
| 40 | 392 | 371 | 402 | 70.4 | 80.4 | 59.5 | 43.1 | 182(1250) |
| 39 | 382 | 362 | 391 | 69.9 | 79.9 | 58.6 | 41.9 | 177(1220) |
| 38 | 372 | 353 | 380 | 69.4 | 79.4 | 57.7 | 40.8 | 171 (1180) |
| 37 | 363 | 344 | 370 | 68.9 | 78.8 | 56.8 | 39.6 | 166 (1140) |
| 36 | 354 | 336 | 360 | 68.4 | 78.3 | 55.9 | 38.4 | 161 (1110) |
| 35 | 345 | 327 | 351 | 67.9 | 77.7 | 55 | 37.2 | 156 (1080) |
| 34 | 336 | 319 | 342 | 67.4 | 77.2 | 54.2 | 36.1 | 152 (1050) |
| 33 | 327 | 311 | 334 | 66.8 | 76.6 | 53.3 | 34.9 | 149 (1030) |
| 32 | 318 | 301 | 326 | 66.3 | 76.1 | 52.1 | 33.7 | 146 (1010) |
| 31 | 310 | 294 | 318 | 65.8 | 75.6 | 51.3 | 32.5 | 141 (970) |
| 30 | 302 | 286 | 311 | 65.3 | 75 | 50.4 | 31.3 | 138 (950) |
| 29 | 294 | 279 | 304 | 64.6 | 74.5 | 49.5 | 30.1 | 135 (930) |
| 28 | 286 | 271 | 297 | 64.3 | 73.9 | 48.6 | 28.9 | 131 (900) |
| 27 | 279 | 264 | 290 | 63.8 | 73.3 | 47.7 | 27.8 | 128 (880) |
| 26 | 272 | 258 | 284 | 63.3 | 72.8 | 46.8 | 26.7 | 125 (860) |
| 25 | 266 | 253 | 278 | 62.8 | 72.2 | 45.9 | 25.5 | 123 (850) |
| 24 | 260 | 247 | 272 | 62.4 | 71.6 | 45 | 24.3 | 119 (820) |
| 23 | 254 | 243 | 266 | 62 | 71 | 44 | 23.1 | 117 (810) |
| 22 | 248 | 237 | 261 | 61.5 | 70.5 | 43.2 | 22 | 115 (790) |
| 21 | 243 | 231 | 256 | 61 | 69.9 | 42.3 | 20.7 | 112 (770) |
| 20 | 238 | 226 | 251 | 60.5 | 69.4 | 41.5 | 19.6 | 110 (760) |
| TABLE 2B Approximate Hardness Conversion Numbers for Nonaustenitic Steels | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| (Rockwell B to other Hardness Numbers) | |||||||||
| Rockwell Superficial Hardness | |||||||||
| Rockwell B Scale, 100-kgf Load 1/16-in. (1.588-mm) Ball | Vickers Hardness Number | Brinell Hardness, 3000-kgf Load, 10-mm Ball | Knoop Hardness, 500-gf Load and Over | Rockwell F Scale, 60-kgf Load 1/16-in. (1.588-mm) Ball | Rockwell F Scale, 60-kgf Load 1/16-in. (1.588-mm) Ball | 15T Scale, 15-kgf Load, 1/16-in. (1.588-mm) Ball | 30T Scale 30-kgf Load, 1/16-in. (1.588-mm) Ball | 45T Scale, 45-kgf Load, 1/16-in. (1.588-mm) Ball | Approximate Tensile Strength, ksi (MPa) |
| 100 | 240 | 240 | 251 | 61.5 | 93.1 | 83.1 | 72.9 | 166(800) | |
| 99 | 234 | 234 | 246 | 60.9 | 92.8 | 82.5 | 71.9 | 114(785) | |
| 98 | 228 | 228 | 241 | 60.2 | 92.5 | 81.8 | 70.9 | 109(750) | |
| 97 | 222 | 222 | 236 | 59.5 | 92.1 | 81.1 | 69.9 | 104(715) | |
| 96 | 216 | 216 | 231 | 58.9 | 91.8 | 80.4 | 68.9 | 102(705) | |
| 95 | 210 | 210 | 226 | 58.3 | 91.5 | 79.8 | 67.9 | 100(690) | |
| 94 | 205 | 205 | 221 | 57.6 | 91.2 | 79.1 | 66.9 | 98(675) | |
| 93 | 200 | 200 | 216 | 57 | 90.8 | 78.4 | 65.9 | 94(650) | |
| 92 | 195 | 195 | 211 | 56.4 | 90.5 | 77.8 | 64.8 | 92(635) | |
| 91 | 190 | 190 | 206 | 55.8 | 90.2 | 77.1 | 63.8 | 90(620) | |
| 90 | 185 | 185 | 201 | 55.2 | 89.9 | 76.4 | 62.8 | 89(615) | |
| 89 | 180 | 180 | 196 | 54.6 | 89.5 | 75.8 | 61.8 | 88(605) | |
| 88 | 176 | 176 | 192 | 54 | 89.2 | 75.1 | 60.8 | 86(590) | |
| 87 | 172 | 172 | 188 | 53.4 | 88.9 | 74.4 | 59.8 | 84(580) | |
| 86 | 169 | 169 | 184 | 52.8 | 88.6 | 73.8 | 58.8 | 83(570) | |
| 85 | 165 | 165 | 180 | 52.3 | 88.2 | 73.1 | 57.8 | 82(565) | |
| 84 | 162 | 162 | 176 | 51.7 | 87.9 | 72.4 | 56.8 | 81(560) | |
| 83 | 159 | 159 | 173 | 51.1 | 87.6 | 71.8 | 55.8 | 80(550) | |
| 82 | 156 | 156 | 170 | 50.6 | 87.3 | 71.1 | 54.8 | 77(530) | |
| 81 | 153 | 153 | 167 | 50 | 86.9 | 70.4 | 53.8 | 73(505) | |
| 80 | 150 | 150 | 164 | 49.5 | 86.6 | 69.7 | 52.8 | 72(495) | |
| 79 | 147 | 147 | 161 | 48.9 | 86.3 | 69.1 | 51.8 | 70(485) | |
| 78 | 144 | 144 | 158 | 48.4 | 86 | 68.4 | 50.8 | 69(475) | |
| 77 | 141 | 141 | 155 | 47.9 | 85.6 | 67.7 | 49.8 | 68(470) | |
| 76 | 139 | 139 | 152 | 47.3 | 85.3 | 67.1 | 48.8 | 67(460) | |
| 75 | 137 | 137 | 150 | 46.8 | 99.6 | 85 | 66.4 | 47.8 | 66(455) |
| 74 | 135 | 135 | 147 | 46.3 | 99.1 | 84.7 | 65.7 | 46.8 | 65(450) |
| 73 | 132 | 132 | 145 | 45.8 | 98.5 | 84.3 | 65.1 | 45.8 | 64(440) |
| 72 | 130 | 130 | 143 | 45.3 | 98 | 84 | 64.4 | 44.8 | 63(435) |
| 71 | 127 | 127 | 141 | 44.8 | 97.4 | 83.7 | 63.7 | 43.8 | 62(425) |
| 70 | 125 | 125 | 139 | 44.3 | 96.8 | 83.4 | 63.1 | 42.8 | 61(420) |
| 69 | 123 | 123 | 137 | 43.8 | 96.2 | 83 | 62.4 | 41.8 | 60(415) |
| 68 | 121 | 121 | 135 | 43.3 | 95.6 | 82.7 | 61.7 | 40.8 | 59(405) |
| 67 | 119 | 119 | 133 | 42.8 | 95.1 | 82.4 | 61 | 39.8 | 58(400) |
| TABLE 2A Approximate Hardness Conversion Numbers for Nonaustenitic Steels | ||||||||
|---|---|---|---|---|---|---|---|---|
| (Rockwell C to other Hardness Numbers) | ||||||||
| Rockwell Superficial Hardness | ||||||||
| Rockwell C Scale, 150-kgf Load, Diamond Penetrator | Vickers Hardness Number | Brinell Hardness, 3000-kgf Load, 10-mm Ball | Knoop Hardness, 500-gf Load and Over | Rockwell A Scale, 60-kgf Load, Diamond Penetrator | 15N Scale, 15-kgf Load, Diamond Penetrator | 30N Scale 30-kgf Load, Diamond Penetrator | 45N Scale, 45-kgf Load, Diamond Penetrator | Approximate Tensile Strength, ksi (MPa) |
| 48 | 484 | 455 | 510 | 74.7 | 84.5 | 66.7 | 52.5 | 238(1640) |
| 47 | 471 | 442 | 495 | 74.1 | 83.9 | 65.8 | 51.4 | 229(1580) |
| 46 | 458 | 432 | 480 | 73.8 | 83.5 | 64.8 | 50.3 | 221(1520) |
| 45 | 446 | 421 | 466 | 73.1 | 83 | 64 | 49 | 215(1480) |
| 44 | 434 | 409 | 452 | 72.5 | 82.5 | 63.1 | 47.8 | 208(1430) |
| 43 | 423 | 400 | 438 | 72 | 82 | 62.2 | 46.7 | 201(1390) |
| 42 | 412 | 390 | 426 | 71.5 | 81.5 | 61.3 | 45.5 | 194(1340) |
| 41 | 402 | 381 | 414 | 70.9 | 80.9 | 60.4 | 44.3 | 188(1300) |
| 40 | 392 | 371 | 402 | 70.4 | 80.4 | 59.5 | 43.1 | 182(1250) |
| 39 | 382 | 362 | 391 | 69.9 | 79.9 | 58.6 | 41.9 | 177(1220) |
| 38 | 372 | 353 | 380 | 69.4 | 79.4 | 57.7 | 40.8 | 171 (1180) |
| 37 | 363 | 344 | 370 | 68.9 | 78.8 | 56.8 | 39.6 | 166 (1140) |
| 36 | 354 | 336 | 360 | 68.4 | 78.3 | 55.9 | 38.4 | 161 (1110) |
| 35 | 345 | 327 | 351 | 67.9 | 77.7 | 55 | 37.2 | 156 (1080) |
| 34 | 336 | 319 | 342 | 67.4 | 77.2 | 54.2 | 36.1 | 152 (1050) |
| 33 | 327 | 311 | 334 | 66.8 | 76.6 | 53.3 | 34.9 | 149 (1030) |
| 32 | 318 | 301 | 326 | 66.3 | 76.1 | 52.1 | 33.7 | 146 (1010) |
| 31 | 310 | 294 | 318 | 65.8 | 75.6 | 51.3 | 32.5 | 141 (970) |
| 30 | 302 | 286 | 311 | 65.3 | 75 | 50.4 | 31.3 | 138 (950) |
| 29 | 294 | 279 | 304 | 64.6 | 74.5 | 49.5 | 30.1 | 135 (930) |
| 28 | 286 | 271 | 297 | 64.3 | 73.9 | 48.6 | 28.9 | 131 (900) |
| 27 | 279 | 264 | 290 | 63.8 | 73.3 | 47.7 | 27.8 | 128 (880) |
| 26 | 272 | 258 | 284 | 63.3 | 72.8 | 46.8 | 26.7 | 125 (860) |
| 25 | 266 | 253 | 278 | 62.8 | 72.2 | 45.9 | 25.5 | 123 (850) |
| 24 | 260 | 247 | 272 | 62.4 | 71.6 | 45 | 24.3 | 119 (820) |
| 23 | 254 | 243 | 266 | 62 | 71 | 44 | 23.1 | 117 (810) |
| 22 | 248 | 237 | 261 | 61.5 | 70.5 | 43.2 | 22 | 115 (790) |
| 21 | 243 | 231 | 256 | 61 | 69.9 | 42.3 | 20.7 | 112 (770) |
| 20 | 238 | 226 | 251 | 60.5 | 69.4 | 41.5 | 19.6 | 110 (760) |
| TABLE 2B Approximate Hardness Conversion Numbers for Nonaustenitic Steels | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| (Rockwell B to other Hardness Numbers) | |||||||||
| Rockwell Superficial Hardness | |||||||||
| Rockwell B Scale, 100-kgf Load 1/16-in. (1.588-mm) Ball | Vickers Hardness Number | Brinell Hardness, 3000-kgf Load, 10-mm Ball | Knoop Hardness, 500-gf Load and Over | Rockwell F Scale, 60-kgf Load 1/16-in. (1.588-mm) Ball | Rockwell F Scale, 60-kgf Load 1/16-in. (1.588-mm) Ball | 15T Scale, 15-kgf Load, 1/16-in. (1.588-mm) Ball | 30T Scale 30-kgf Load, 1/16-in. (1.588-mm) Ball | 45T Scale, 45-kgf Load, 1/16-in. (1.588-mm) Ball | Approximate Tensile Strength, ksi (MPa) |
| 100 | 240 | 240 | 251 | 61.5 | 93.1 | 83.1 | 72.9 | 166(800) | |
| 99 | 234 | 234 | 246 | 60.9 | 92.8 | 82.5 | 71.9 | 114(785) | |
| 98 | 228 | 228 | 241 | 60.2 | 92.5 | 81.8 | 70.9 | 109(750) | |
| 97 | 222 | 222 | 236 | 59.5 | 92.1 | 81.1 | 69.9 | 104(715) | |
| 96 | 216 | 216 | 231 | 58.9 | 91.8 | 80.4 | 68.9 | 102(705) | |
| 95 | 210 | 210 | 226 | 58.3 | 91.5 | 79.8 | 67.9 | 100(690) | |
| 94 | 205 | 205 | 221 | 57.6 | 91.2 | 79.1 | 66.9 | 98(675) | |
| 93 | 200 | 200 | 216 | 57 | 90.8 | 78.4 | 65.9 | 94(650) | |
| 92 | 195 | 195 | 211 | 56.4 | 90.5 | 77.8 | 64.8 | 92(635) | |
| 91 | 190 | 190 | 206 | 55.8 | 90.2 | 77.1 | 63.8 | 90(620) | |
| 90 | 185 | 185 | 201 | 55.2 | 89.9 | 76.4 | 62.8 | 89(615) | |
| 89 | 180 | 180 | 196 | 54.6 | 89.5 | 75.8 | 61.8 | 88(605) | |
| 88 | 176 | 176 | 192 | 54 | 89.2 | 75.1 | 60.8 | 86(590) | |
| 87 | 172 | 172 | 188 | 53.4 | 88.9 | 74.4 | 59.8 | 84(580) | |
| 86 | 169 | 169 | 184 | 52.8 | 88.6 | 73.8 | 58.8 | 83(570) | |
| 85 | 165 | 165 | 180 | 52.3 | 88.2 | 73.1 | 57.8 | 82(565) | |
| 84 | 162 | 162 | 176 | 51.7 | 87.9 | 72.4 | 56.8 | 81(560) | |
| 83 | 159 | 159 | 173 | 51.1 | 87.6 | 71.8 | 55.8 | 80(550) | |
| 82 | 156 | 156 | 170 | 50.6 | 87.3 | 71.1 | 54.8 | 77(530) | |
| 81 | 153 | 153 | 167 | 50 | 86.9 | 70.4 | 53.8 | 73(505) | |
| 80 | 150 | 150 | 164 | 49.5 | 86.6 | 69.7 | 52.8 | 72(495) | |
| 79 | 147 | 147 | 161 | 48.9 | 86.3 | 69.1 | 51.8 | 70(485) | |
| 78 | 144 | 144 | 158 | 48.4 | 86 | 68.4 | 50.8 | 69(475) | |
| 77 | 141 | 141 | 155 | 47.9 | 85.6 | 67.7 | 49.8 | 68(470) | |
| 76 | 139 | 139 | 152 | 47.3 | 85.3 | 67.1 | 48.8 | 67(460) | |
| 75 | 137 | 137 | 150 | 46.8 | 99.6 | 85 | 66.4 | 47.8 | 66(455) |
| 74 | 135 | 135 | 147 | 46.3 | 99.1 | 84.7 | 65.7 | 46.8 | 65(450) |
| 73 | 132 | 132 | 145 | 45.8 | 98.5 | 84.3 | 65.1 | 45.8 | 64(440) |
| 72 | 130 | 130 | 143 | 45.3 | 98 | 84 | 64.4 | 44.8 | 63(435) |
| 71 | 127 | 127 | 141 | 44.8 | 97.4 | 83.7 | 63.7 | 43.8 | 62(425) |
| 70 | 125 | 125 | 139 | 44.3 | 96.8 | 83.4 | 63.1 | 42.8 | 61(420) |
| 69 | 123 | 123 | 137 | 43.8 | 96.2 | 83 | 62.4 | 41.8 | 60(415) |
| 68 | 121 | 121 | 135 | 43.3 | 95.6 | 82.7 | 61.7 | 40.8 | 59(405) |
| 67 | 119 | 119 | 133 | 42.8 | 95.1 | 82.4 | 61 | 39.8 | 58(400) |
We’re thrilled you’re interested in a new business opportunity and potential partnership. Submit your business inquiry here and our sales team will connect with you shortly.
