Hardness Conversation Table
Brinell   Rockwell   Tensile Brinell   Rockwell   Tensile
Indent Number* B C Strength Indent Number* B C Strength
Dia./mm       1000psi Dia./mm       1000psi
2.25 745   65.3   3.75 262 103 26.6 127
2.3 712   -   3.8 255 102 25.4 123
2.35 682   61.7   3.85 248 101 24.2 120
2.4 653   60   3.9 241 100 22.8 116
2.45 627   58.7   3.95 235 99 21.7 114
2.5 601   57.3   4 229 98.2 20.5 111
2.55 578   56   4.05 223 97.3 18.8 -
2.6 555   54.7 298 4.1 217 96.4 17.5 105
2.65 534   53.5 288 4.15 212 95.5 16 102
2.7 514   52.1 274 4.2 207 94.6 15.2 100
2.75 495   51.6 269 4.25 201 93.8 13.8 98
2.8 477   50.3 258 4.3 197 92.8 12.7 95
2.85 461   48.8 244 4.35 192 91.9 11.5 93
2.9 444   47.2 231 4.4 187 90.7 10 90
2.95 429   45.7 219 4.45 183 90 9 89
3 415   44.5 212 4.5 179 89 8 87
3.05 401   43.1 202 4.55 174 87.8 6.4 85
3.1 388   41.8 193 4.6 170 86.8 5.4 83
3.15 375   40.4 184 4.65 167 86 4.4 81
3.2 363   39.1 177 4.7 163 85 3.3 79
3.25 352 110 37.9 171 4.8 156 82.9 0.9 76
3.3 341 109 36.6 164 4.9 149 80.8   73
3.35 331 108.5 35.5 159 5 143 78.7   71
3.4 321 108 34.3 154 5.1 137 76.4   67
3.45 311 107.5 33.1 149 5.2 131 74   65
3.5 302 107 32.1 146 5.3 126 72   63
3.55 293 106 30.9 141 5.4 121 69.8   60
3.6 285 105.5 29.9 138 5.5 116 67.6   58
3.65 277 104.5 28.8 134 5.6 111 65.7   56
3.7 269 104 27.6 130          
Condensation of Table 2, Report J417b, SAE 1980 handbook.
* Values above 500 are for tungsten carbide ball; below 500 for standard ball.
2000 Mercatech, Inc.