Modified Stock Gearing - Boston Gear

Spur Gears
Approximate Horsepower and Torque* Ratings
For Class I Service (Service Factor = 1.0)
8 DIAMETRAL PITCH STEEL 14 1 ⁄2° PRESSURE ANGLE 1-1/4" FACE REFERENCE PAGE 24.
No. 25 RPM 50 RPM 100 RPM 200 RPM 300 RPM 600 RPM 900 RPM 1200 RPM 1800 RPM 3600 RPM
Teeth H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque
11 .18 446 .35 439 .68 427 1.28 404 1.82 383 3.16 332 4.19 294 5.00 263 6.21 217 8.17 143
12 .19 485 .38 478 .73 463 1.38 436 1.96 412 3.37 354 4.43 310 5.26 276 6.47 226 8.39 147
14 .25 632 .49 620 .95 599 1.77 559 2.49 524 4.21 442 5.45 382 6.40 336 7.75 271 9.81 172
15 .28 703 .55 690 1.05 664 1.96 617 2.74 576 4.58 481 5.90 413 6.89 362 8.29 290 10.39 182
16 .31 778 .60 762 1.16 731 2.15 677 3.00 630 4.97 522 6.36 445 7.39 388 8.83 309 10.96 192
18 .37 927 .72 905 1.37 865 2.52 794 3.49 734 5.69 598 7.20 504 8.30 436 9.80 343
20 .43 1075 .83 1047 1.58 996 2.88 907 3.96 832 6.35 667 7.96 557 9.10 478 10.64 372
22 .48 1219 .94 1184 1.78 1121 3.21 1012 4.39 923 6.95 730 8.62 603 9.79 514 11.34 397
24 .54 1355 1.04 1313 1.96 1237 3.52 1109 4.78 1004 7.46 783 9.17 642 10.36 544 11.90 417
28 .66 1655 1.27 1596 2.37 1490 4.18 1316 5.61 1178 8.53 896 10.33 723 11.54 606
30 .71 1786 1.36 1718 2.53 1598 4.44 1400 5.93 1247 8.93 938 10.73 752 11.94 627
32 .78 1957 1.49 1878 2.76 1738 4.80 1513 6.38 1340 9.49 997 11.34 794 12.56 660
A
8 DIAMETRAL PITCH CAST IRON 14 1 ⁄2° PRESSURE ANGLE 1-1/4" FACE REFERENCE PAGE 25.
No. 25 RPM 50 RPM 100 RPM 200 RPM 300 RPM 600 RPM 900 RPM 1200 RPM 1800 RPM 3600 RPM
Teeth H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque
36 .53 1339 1.01 1279 1.86 1174 3.20 1009 4.21 884 6.14 645 7.25 507
40 .60 1508 1.14 1434 2.07 1305 3.51 1107 4.57 961 6.55 688 7.66 536
42 .63 1579 1.19 1498 2.16 1358 3.63 1145 4.71 989 6.69 703 7.78 545
44 .67 1681 1.26 1591 2.28 1437 3.82 1204 4.93 1036 6.95 730 8.05 564
48 .72 1824 1.36 1719 2.44 1540 4.05 1275 5.18 1088 7.19 756 8.27 579
54 .83 2092 1.55 1958 2.75 1735 4.48 1413 5.67 1192 7.72 811
56 .86 2164 1.60 2021 2.83 1784 4.59 1446 5.78 1215 7.83 822
60 .92 2307 1.70 2145 2.98 1880 4.79 1508 5.99 1259 8.01 842
64 .99 2492 1.83 2307 3.19 2008 5.06 1595 6.30 1323 8.33 875
72 1.10 2775 2.02 2548 3.47 2188 5.42 1707 6.66 1399 8.64 908
80 1.23 3107 2.24 2828 3.81 2398 5.84 1839 7.10 1492 9.06 952
84 1.29 3246 2.34 2943 3.94 2481 5.99 1887 7.25 1523 9.18 965
88 1.34 3384 2.42 3056 4.06 2561 6.13 1933 7.39 1553 9.30 976
96 1.45 3656 2.60 3277 4.31 2713 6.41 2019 7.65 1608 9.50 998
112 1.69 4256 2.98 3757 4.83 3045 7.01 2207 8.24 1731
120 1.79 4517 3.14 3960 5.04 3176 7.22 2275 8.44 1773
128 1.89 4773 3.30 4155 5.24 3300 7.42 2339 8.62 1811
144 2.09 5272 3.59 4528 5.60 3532 7.78 2452
160 2.33 5868 3.95 4980 6.07 3828 8.28 2610
8 DIAMETRAL PITCH NON-METALLIC 14 1 ⁄2° PRESSURE ANGLE 1-1/4" FACE REFERENCE PAGE 24.
No. 25 RPM 50 RPM 100 RPM 200 RPM 300 RPM 600 RPM 900 RPM 1200 RPM 1800 RPM 3600 RPM
Teeth H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque
16 .56 176 .76 160 1.23 129 1.61 112 1.96 103 2.60 91 4.39 77
18 .61 192 .88 185 1.41 148 1.84 129 2.25 118 3.00 105 4.71 82
20 .74 233 .99 208 1.59 167 2.08 146 2.54 133 3.40 119 5.84 102
24 .90 283 1.19 250 1.90 200 2.50 175 3.06 160 4.13 144 7.22 126
28 1.06 334 1.38 290 2.20 231 2.91 204 3.57 187 4.86 170
6 DIAMETRAL PITCH STEEL 14 1 ⁄2° PRESSURE ANGLE 1-1/2" FACE REFERENCE PAGE 25.
No. 25 RPM 50 RPM 100 RPM 200 RPM 300 RPM 600 RPM 900 RPM 1200 RPM 1800 RPM 3600 RPM
Teeth H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque H.P. Torque
11 .38 946 .74 928 1.42 893 2.64 832 3.70 778 6.20 652 8.01 561 9.37 492 11.29 395 14.19 249
12 .41 1030 .80 1008 1.54 968 2.84 896 3.97 834 6.57 691 8.41 589 9.78 514 11.69 409 14.51 254
14 .53 1340 1.04 1308 1.98 1247 3.62 1142 5.01 1053 8.12 853 10.24 717 11.77 618 13.85 485
15 .59 1491 1.15 1452 2.19 1381 3.99 1257 5.49 1154 8.81 925 11.03 773 12.62 663 14.75 517
16 .65 1648 1.27 1603 2.41 1519 4.37 1376 5.98 1257 9.51 999 11.83 828 13.47 708 15.65 548
18 .78 1962 1.51 1902 2.84 1792 5.10 1606 6.92 1455 10.80 1135 13.28 930 15.00 788 17.23 603
20 .90 2273 1.74 2196 3.26 2057 5.79 1825 7.81 1640 11.97 1258 14.57 1020 16.33 858
21 .97 2436 1.86 2349 3.48 2194 6.15 1937 8.25 1734 12.56 1319 15.20 1065 16.99 892
24 1.13 2860 2.18 2745 4.03 2541 7.02 2212 9.32 1958 13.87 1457 16.57 1160 18.35 964
27 1.32 3335 2.53 3186 4.64 2924 7.97 2512 10.48 2201 15.29 1606 18.05 1264
30 1.49 3761 2.84 3576 5.17 3255 8.76 2761 11.41 2396 16.35 1717 19.10 1338
Ratings are based on strength calculation. Basic static strength rating, or for hand operation of above gears is approximately 3 times the 100 RPM rating.
NOTE: Ratings to right of heavy line are not recommended, as pitch line velocity exceeds 1000 feet per minute.
They should be used for interpolation purposes only.
*Torque Ratings (Lb. Ins.).
P-1930-BG 04/10 Boston Gear 800-825-6544 55