TM 9-254 5-9. Screw Thread - Continued Table 5-10.  Basic Coarse Thread Dimensions and Tap Drill Sizes - American Machine Screw - Continued Commercial Decimal Nominal size Outside Pitch Root tap drill to equivalent diameter diameter diameter produce approx of tap Inch Threads (in.) (in.) (in.) 75 percent drill per inch full thread 5-36 .1250 .1078 .0889 40 .0980 40 .1250 .1088 .0925 38 .1015 44 .1250 .1102 .0955 37 .1040 6-32 .1380 .1177 .0974 36 .1065 36 .1380 .1200 .1019 34 .1110 40 .1380 .1218 .1055 33 .1130 7-30 .1510 .1294 .1077 31 .1200 32 .1510 .1307 .1104 31 .1200 36 .1510 .1330 .1149 1/8 .1250 8-30 .1640 .1423 .1207 30 .1285 32 .1640 .1437 .1234 29 .1360 36 .1640 .1460 .1279 29 .1360 40 .1640 .1478 .1315 28 .1405 9-24 .1770 .1499 .1229 29 .1360 30 .1770 .1553 .1337 21 .1590 12-24 .2160 .1889 .1619 16 .1770 28 .2160 .1928 .1696 14 .1820 32 .2160 .1957 .1754 13 .1850 5-23