Общий каталог OSG 2018 - 2019 - страница 671

Tap Drill Size Tap Drill Sizes - Fractional Cut Taps To minimize tapping problems and lengthen tool life, use Suggested Percentage of Full Thread in Tapped Holes the largest drill possible to produce a minor diameter thatwill result in the lowest percentage of full thread consistentMaterial*Deep Hole Average Thin Sheet StockTappingCommercial Workor Stamping with adequate strength. A minor diameter that provides a55% to 65% thread is sufficient for most requirements, but insome cases a higher percentage of thread may be necessaryFreeCuttingAluminum, Brass, Bronze,Cast Iron, Copper, Mild Steel,Tool Steel60% - 70%65% - 70%75% - 85% to conform with the minor diameter limits of the thread classspecified. Hard or Cast Steel, DropToughForging, Monel Metal, Nickel55% - 65%60% - 70% * Generally, deeper than 1-1/2 times the hole diameter. Cutting Steel, Stainless Steel Threads Per Inch Minor Diameter Tap Drill Diameter - Cut Taps Tap Size 80% Thread 75% Thread 70% Thread 65% Thread 60% Thread UNC UNF 8-Pitch Min. 2B Max. 2B (in) (in) (in) (in) (in) 0 – 80 – 0.0465 0.0514 0.0470 0.0478 0.0486 0.0494 0.0503 1 64 – – 0.0561 0.0623 0.0568 0.0578 0.0588 0.0598 0.0608–72–0.05800.06350.05860.05950.06040.06130.0622 2 56 – – 0.0667 0.0737 0.0674 0.0686 0.0698 0.0709 0.0721–64–0.06910.07520.06980.07080.07180.07280.0738 3 48 – – 0.0764 0.0845 0.0774 0.0787 0.0801 0.0814 0.0828–56–0.07970.08650.08040.08160.08280.08390.0851 4 40 – – 0.0849 0.0939 0.0860 0.0876 0.0893 0.0909 0.0925–48–0.08940.09680.09040.09170.09310.09440.0958 5 40 – – 0.0979 0.1062 0.0990 0.1006 0.1023 0.1039 0.1055–44–0.10040.10790.10140.10290.10430.10580.1073 6 32 – – 0.1040 0.1140 0.1055 0.1076 0.1096 0.1116 0.1136–40–0.11100.11900.11200.11360.11530.11690.1185 8 32 – – 0.1300 0.1390 0.1315 0.1336 0.1356 0.1376 0.1396–36–0.13400.14200.13510.13690.13870.14050.1424 10 24 – – 0.1450 0.1560 0.1467 0.1494 0.1521 0.1548 0.1575–32–0.15600.16400.15750.15960.16160.16360.1656 12 24 – – 0.1710 0.1810 0.1727 0.1754 0.1781 0.1808 0.1835–28–0.17700.18600.17890.18120.18350.18580.1882 1/4 20 – – 0.1960 0.2070 0.1980 0.2013 0.2045 0.2078 0.2110–28–0.21100.22000.21290.21520.21750.21980.2222 5/16 18 – – 0.2520 0.2650 0.2548 0.2584 0.2620 0.2656 0.2692–24–0.26700.27700.26920.27190.27460.27730.2800 3/8 16 – – 0.3070 0.3210 0.3101 0.3141 0.3182 0.3222 0.3263–24–0.33000.34000.33170.33440.33710.33980.3425 7/16 14 – – 0.3600 0.3760 0.3633 0.3679 0.3726 0.3772 0.3818–20–0.38300.39500.38550.38880.39200.39530.3985 1/2 13 – – 0.4170 0.4340 0.4201 0.4251 0.4301 0.4351 0.4400–20–0.44600.45700.44800.45130.45450.45780.4610 9/16 12 – – 0.4720 0.4900 0.4759 0.4813 0.4867 0.4921 0.4976–18–0.50200.51500.50480.50840.51200.51560.5192 5/8 11 – – 0.5270 0.5460 0.5305 0.5364 0.5423 0.5482 0.5541–18–0.56500.57800.56730.57090.57450.57810.5817 3/4 10 – – 0.6420 0.6630 0.6461 0.6526 0.6591 0.6656 0.6721–16–0.68200.69600.68510.68910.69320.69720.7013 7/8 9 – – 0.7550 0.7780 0.7595 0.7668 0.7740 0.7812 0.7884–14–0.79800.81400.80080.80540.81010.81470.8193 1 8 – – 0.8650 0.8900 0.8701 0.8782 0.8863 0.8945 0.9026–12–0.91000.92800.91340.91880.92420.92960.9351 7 – – 0.9700 0.9980 0.9765 0.9858 0.9951 1.0044 1.0137 1-1/8 – 12 – 1.0350 1.0530 1.0384 1.0438 1.0492 1.0546 1.0601 – – 8 0.9900 1.0150 0.9951 1.0032 1.0113 1.0195 1.0276 7 – – 1.0950 1.1230 1.1015 1.1108 1.1201 1.1294 1.1387 1-1/4 – 12 – 1.1600 1.1780 1.1634 1.1688 1.1742 1.1796 1.1851 – – 8 1.1150 1.1400 1.1201 1.1282 1.1363 1.1445 1.1526 6 – – 1.1950 1.2250 1.2018 1.2126 1.2235 1.2343 1.2451 1-3/8 – 12 – 1.2850 1.3030 1.2884 1.2938 1.2992 1.3046 1.3101 – – 8 1.2400 1.2650 1.2451 1.2532 1.2613 1.2695 1.2776 6 – – 1.3200 1.3500 1.3268 1.3376 1.3485 1.3593 1.3701 1-1/2 – 12 – 1.4100 1.4280 1.4134 1.4188 1.4242 1.4296 1.4351 – – 8 1.3650 1.3900 1.3701 1.3782 1.3863 1.3945 1.4026 1-5/8 – – 8 1.4900 1.5150 1.4951 1.5032 1.5113 1.5195 1.5276 1-3/4 5 – – 1.5330 1.5670 1.5422 1.5551 1.5681 1.5811 1.5941––81.61501.64001.62011.62821.63631.64451.6526 1-7/8 – – 8 1.7400 1.7650 1.7451 1.7532 1.7613 1.7695 1.7776 2 4-1/2 – – 1.7590 1.7950 1.7691 1.7835 1.7979 1.8124 1.8268––81.86501.89001.87011.87821.88631.89451.9026 2-1/4 4-1/2 ––– – 2.0090 2.0450 2.0191 2.0335 2.0479 2.0624 2.076882.11502.14002.12012.12822.13632.14452.1526 2-1/2 4 – – 2.2290 2.2670 2.2402 2.2564 2.2727 2.2889 2.3051––82.36502.39002.37012.37822.38632.39452.4026 FORMULA: TAP DRILL SIZE FORMULA: PERCENTAGE OF FULL THREAD Drill Size = Tap Major Dia - 0.01299 x % of Full Thread# of Threads Per Inch % of Full Thread = Threads Per Inch x Tap Major Dia - Drill Dia0.01299 Example: Determine Drill Size for 2”—12N Tap,70% Full Thread. Example: Determine the % of Full Thread for 2”—12N Tap, using 1.9242” Drill. Basic Major Diameter of Tap = 2.0000” Threads Per Inch = 12 0.01299 x 70 = 0.9093 ÷ 12 = 0.0758” 2.000-1.9242 =0.0758 ÷ 0.01299 = 5.835 Drill Size = 1.9242” Percentage of Full Threads = 70% WWW.OSGTOOL.COM Threading Technical 671