CONVERSTION CHART
HARDNESS CONVERSION CHART
| TABLE 2A Approximate Hardness Conversion Numbers for Nonaustenitic Steelsˆ | ||||||||
| (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 | 73.6 | 83.5 | 64.8 | 50.3 | 221 (1520) |
| 45 | 446 | 421 | 466 | 73.1 | 83.0 | 64.0 | 49.0 | 215 (1480) |
| 44 | 434 | 409 | 452 | 72.5 | 82.5 | 63.1 | 47.8 | 208 (1430) |
| 43 | 423 | 400 | 438 | 72.0 | 82.0 | 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 | 55.0 | 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 | 75.0 | 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 | 45.0 | 24.3 | 119 (820) |
| 23 | 254 | 243 | 266 | 62.0 | 71.0 | 44.0 | 23.1 | 117 (810) |
| 22 | 248 | 237 | 261 | 61.5 | 70.5 | 43.2 | 22.0 | 115 (790) |
| 21 | 243 | 231 | 256 | 61.0 | 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 | 57.0 | … | 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 | 54.0 | … | 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 | 50.0 | … | 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 | … | 86.0 | 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 | 85.0 | 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 | 98.0 | 84.0 | 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 | 83.0 | 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 | 61.0 | 39.8 | 58(400) |
SURFACE ROUGHNESS
| Ra (micrometers) | Ra (microinches) | RMS | CLA (N) | Rt | N | Cut-off Length | |
| inch | mm | ||||||
| 0.025 | 1 | 1.1 | 1 | 0.3 | 1 | 0.003 | 0.08 |
| 0.05 | 2 | 2.2 | 2 | 0.5 | 2 | 0.01 | 0.25 |
| 0.1 | 4 | 4.4 | 4 | 0.8 | 3 | 0.01 | 0.25 |
| 0.2 | 8 | 8.8 | 8 | 1.2 | 4 | 0.01 | 0.25 |
| 0.4 | 16 | 17.6 | 16 | 2.0 | 5 | 0.01 | 0.25 |
| 0.8 | 32 | 32.5 | 32 | 4.0 | 6 | 0.03 | 0.8 |
| 1.6 | 63 | 64.3 | 63 | 8.0 | 7 | 0.03 | 0.8 |
| 3.2 | 125 | 137.5 | 125 | 13 | 8 | 0.1 | 2.5 |
| 6.3 | 250 | 275 | 250 | 25 | 9 | 0.1 | 2.5 |
| 12.5 | 500 | 550 | 500 | 50 | 10 | 0.1 | 2.5 |
| 25.0 | 1000 | 1100 | 1000 | 100 | 11 | 0.3 | 8.0 |
| 50.0 | 2000 | 2200 | 2000 | 200 | 12 | 0.3 | 8.0 |
| Ra = | Roughness Average in micrometers or microinches. | ||||||
| RMS = | Root Mean Square in microinches | ||||||
| CLA = | Center Line Average in Microinches | ||||||
| Rt = | Roughness Ttal in microns | ||||||
| N = | New ISO (grade) scale numbers | ||||||
| Порезка = | Length required for sample. | ||||||
INCHES TO MM
| inch | Metric(mm) | inch | Metric(mm) |
| 1/4 | 6.35 | 3 | 76.2 |
| 5/16 | 7.94 | 3 1/8 | 79.37 |
| 3/8 | 9.53 | 3 1/4 | 82.55 |
| 7/16 | 11.11 | 3 3/8 | 85.72 |
| 1/2 | 12.7 | 3 1/2 | 88.9 |
| 9/16 | 14.29 | 3 5/8 | 92.07 |
| 5/8 | 15.88 | 3 3/4 | 95.25 |
| 11/16 | 17.46 | 3 7/8 | 98.42 |
| 3/4 | 19.05 | 4 | 101.6 |
| 13/16 | 20.64 | 4 1/8 | 104.77 |
| 7/8 | 22.23 | 4 1/4 | 107.95 |
| 15/16 | 23.81 | 4 3/8 | 111.12 |
| 1 | 25.4 | 4 1/2 | 114.3 |
| 1 1/8 | 28.57 | 4 5/8 | 117.47 |
| 1 1/4 | 31.75 | 4 3/4 | 120.65 |
| 1 3/8 | 34.93 | 4 7/8 | 123.82 |
| 1 1/2 | 38.1 | 5 | 127 |
| 1 5/8 | 41.28 | 5 1/8 | 130.17 |
| 1 3/4 | 44.45 | 5 1/4 | 133.52 |
| 1 7/8 | 47.63 | 5 3/8 | 136.8 |
| 2 | 50.8 | 5 1/2 | 139.7 |
| 2 1/8 | 53.97 | 5 5/8 | 142.87 |
| 2 1/4 | 57.15 | 5 3/4 | 146.05 |
| 2 3/8 | 60.32 | 5 7/8 | 149.22 |
| 2 1/2 | 63.5 | 6 | 152.4 |
| 2 5/8 | 66.67 | 6 1/8 | 155.57 |
| 2 3/4 | 69.85 | 6 1/4 | 158.75 |
| 2 7/8 | 73.02 | 6 3/8 | 161.92 |
FEET TO MM
| Feet (ft’) | Meter (Mtr) | Feet (ft’) | Meter (Mtr) |
| 1 | 0.3 | 21 | 6.4 |
| 2 | 0.61 | 22 | 6.71 |
| 3 | 0.91 | 23 | 7.01 |
| 4 | 1.22 | 24 | 7.32 |
| 5 | 1.52 | 25 | 7.62 |
| 6 | 1.83 | 26 | 7.92 |
| 7 | 2.13 | 27 | 8.23 |
| 8 | 2.44 | 28 | 8.53 |
| 9 | 2.74 | 29 | 8.84 |
| 10 | 3.05 | 30 | 9.14 |
| 11 | 3.35 | 31 | 9.45 |
| 12 | 3.66 | 32 | 9.75 |
| 13 | 3.96 | 33 | 10.06 |
| 14 | 4.27 | 34 | 10.36 |
| 15 | 4.57 | 35 | 10.67 |
| 16 | 4.88 | 36 | 10.97 |
| 17 | 5.18 | 37 | 11.28 |
| 18 | 5.49 | 38 | 11.58 |
| 19 | 5.79 | 39 | 11.89 |
| 20 | 6.1 | 40 | 12.19 |