DECIMAL EQUIVALENTS

Decimal Decimal Decimal Decimal Decimal

Size Inches Size Inches Size Inches Size Inches Size Inches
0.25 .0098 2.05 .0807 4.70 .1850 8.40 .3307 14.25 .5610
0.30 .0118 #46 .0810 #13 .1850 Q .3320 9/16 .5625
#80 .0135 #45 .0820 3/16 .1875 8.50 .3346 14.50 .5709
0.35 .0138 2.10 .0827 4.80 .1890 8.60 .3386 37/64 .5781
#79 .0145 2.15 .0846 #12 .1890 R .3390 14.75 .5807
1/64 .0156 #44 .0860 #11 .1910 8.70 .3425 15.00 .5906
0.40 .0157 2.20 .0866 4.90 .1929 11/32 .3437 19/32 .5937
#78 .0160 2.25 .0886 #10 .1935 8.80 .3465 15.25 .6004
0.45 .0177 #43 .0890 #9 .1960 S .3480 39/64 .6094
#77 .0180 2.30 .0905 5.00 .1968 8.90 .3504 15.50 .6102
0.50 .0197 2.35 .0925 #8 .1990 9.00 .3543 15.75 .6201
#76 .0200 #42 .0935 5.10 .2008 T .3580 5/8 .6250
#75 .0210 3/32 .0937 #7 .2010 9.10 .3583 16.00 .6299
0.55 .0217 2.40 .0945 13/64 .2031 23/64 .3594 16.25 .6398
#74 .0225 #41 .0960 #6 .2040 9.20 .3622 41/64 .6406
0.60 .0236 2.45 .0965 5.20 .2047 9.30 .3661 16.50 .6496
#73 .0240 #40 .0980 #5 .2055 U .3680 21/32 .6562
#72 .0250 2.50 .0984 5.30 .2087 9.40 .3701 16.75 .6594
0.65 .0256 #39 .0995 #4 .2090 9.50 .3740 17.00 .6693
#71 .0260 2.55 .1004 5.40 .2126 3/8 .3750 43/64 .6719
0.70 .0276 #38 .1015 #3 .2130 V .3770 17.25 .6791
#70 .0280 2.60 .1024 5.50 .2165 9.60 .3780 11/16 .6875
#69 .0292 #37 .1040 7/32 .2187 9.70 .3819 17.50 .6890
0.75 .0295 2.65 .1043 5.60 .2205 9.80 .3858 17.75 .6988
#68 .0310 2.70 .1063 #2 .2210 W .3860 45/64 .7031
1/32 .0313 #36 .1065 5.70 .2244 9.90 .3898 18.00 .7087
0.80 .0315 2.75 .1083 #1 .2280 25/64 .3906 18.25 .7185
#67 .0320 7/64 .1093 5.80 .2283 10.00 .3937 23/32 .7187
#66 .0330 #35 .1100 5.90 .2323 X .3970 18.50 .7283
0.85 .0335 2.80 .1102 A .2340 10.10 .3976 47/64 .7344
#65 .0350 #34 .1110 15/64 .2344 10.20 .4016 18.75 .7382
0.90 .0354 2.85 .1122 6.00 .2362 Y .4040 19.00 .7480
#64 .0360 #33 .1130 B .2380 10.30 .4055 3/4 .7500
#63 .0370 2.90 .1142 6.10 .2401 13/32 .4062 19.25 .7579
0.95 .0374 #32 .1160 C .2420 10.40 .4094 49/64 .7656
#62 .0380 2.95 .1161 6.20 .2441 Z .4130 19.50 .7677
#61 .0390 3.00 .1181 D .2460 10.50 .4134 19.75 .7776
1.00 .0394 #31 .1200 6.30 .2480 10.60 .4173 25/32 .7812
#60 .0400 3.10 .1220 E-1/4 .2500 10.70 .4213 20.00 .7874
#59 .0410 1/8 .1250 6.40 .2520 27/64 .4219 51/64 .7969
1.05 .0413 3.20 .1260 6.50 .2559 10.80 .4252 20.25 .7972
#58 .0420 #30 .1285 F .2570 10.90 .4291 20.50 .8071
#57 .0430 3.30 .1299 6.60 .2598 11.00 .4330 13/16 .8125
1.10 .0433 3.40 .1339 G .2610 11.10 .4370
1.15 .0453 #29 .1360 6.70 .2638 7/16 .4375 20.75 .8169
21.00 .8268
#56 .0465 3.50 .1378 17/64 .2656 11.20 .4409 53/64 .8281
3/64 .0469 #28 .1405 H .2660 11.30 .4449 21.25 .8366
1.20 .0472 9/64 .1406 6.80 .2677 11.40 .4488 27/32 .8437
1.25 .0492 3.60 .1417 6.90 .2716 11.50 .4528
1.30 .0512 #27 .1440 I .2720 29/64 .4531 21.50 .8465
21.75 .8563
#55 .0520 3.70 .1457 7.00 .2756 11.60 .4567 55/64 .8594
1.35 .0531 #26 .1470 J .2770 11.70 .4606 22.00 .8661
1.40 .0550 #25 .1495 7.10 .2795 11.80 .4646 7/8 .8750
#54 .0550 3.80 .1496 K .2810 11.90 .4685
1.45 .0571 #24 .1520 9/32 .2812 15/32 .4687 22.25 .8760
22.50 .8858
1.50 .0591 3.90 .1535 7.20 .2835 12.00 .4724 57/64 .8906
#53 .0595 #23 .1540 7.30 .2874 12.10 .4764 22.75 .8957
1.55 .0610 5/32 .1562 L .2900 12.20 .4803 23.00 .9055
1/16 .0625 #22 .1570 7.40 .2913 12.30 .4843
1.60 .0629 4.00 .1575 M .2950 31/64 .4843 29/32 .9062
23.25 .9154
#52 .0635 #21 .1590 7.50 .2953 12.40 .4882 59/64 .9219
1.65 .0650 #20 .1610 19/64 .2968 12.50 .4921 23.50 .9252
1.70 .0669 4.10 .1614 7.60 .2992 12.60 .4961 23.75 .9350
#51 .0670 4.20 .1654 N .3020 12.70 .5000
1.75 .0689 #19 .1660 7.70 .3031 1/2 .5000 15/16 .9375
24.00 .9449
#50 .0700 4.30 .1693 7.80 .3071 12.80 .5039 61/64 .9531
1.80 .0709 #18 .1695 7.90 .3110 12.90 .5079 24.25 .9547
1.85 .0730 11/64 .1719 5/16 .3125 13.00 .5118 24.50 .9646
#49 .0730 #17 .1730 8.00 .3150 33/64 .5156
1.90 .0748 4.40 .1732 O .3160 13.20 .5197 31/32 .9688
24.75 .9744
#48 .0760 #16 .1770 8.10 .3189 17/32 .5313 25.00 .9843
1.95 .0768 4.50 .1771 8.20 .3228 13.50 .5315 63/64 .9844
5/64 .0781 #15 .1800 P .3230 13.80 .5433 1” 1.0000
#47 .0785 4.60 .1811 8.30 .3268 35/64 .5469
2.00 .0787 #14 .1820 21/64 .3281 14.00 .5512
 Tap Drill Sizes
(Drill sizes based on approximate 72-77% full thread)

Tap Alt. Tap Alt. Tap Alt.

Tap Size/ Drill Tap Tap Size/ Drill Tap Tap Size/ Drill Tap
Pitch Form Size Drill Pitch Form Size Drill Pitch Form Size Drill
Unified Taps Taper Pipe Taps - NPT 27 - 3.00 61/64 24.00
0 - 80 3/64 1.25 1/16 - 27 D 6.30 30 - 3.50 1-3/64 26.50
1 - 64 UNC 53 1.55 1/8 - 27 R 8.70 33 - 3.50 1-5/32 29.50
1 - 72 UNF 53 1.55 1/4 - 18 7/16 11.10 36 - 4.00 1-1/4 32.00
2 - 56 UNC 51 1.85 3/8 - 18 37/64 14.50 39 - 4.00 1-3/8 35.00
2 - 64 UNF 50 1.90 1/2 - 14 23/32 18.00 I.S.O. Metric Fine
3 - 48 UNC 47 2.10 3/4 - 14 59/64 23.25 3 - 0.35 37 2.65
3 - 56 UNF 46 2.15 1 - 11.5 1.5/32 29.00 4 - 0.35 27 3.65
4 - 40 UNC 43 2.35 1.1/4 - 11.5 1.1/2 38.00 4 - 0.50 29 3.50
4 - 48 UNF 42 2.40 1.1/2 - 11.5 1.47/64 44.00 4.5 - 0.45 21 4.05
5 - 40 UNC 39 2.65 2” - 11.5 2.7/32 57.00 5 - 0.50 16 4.50
5 - 44 UNF 37 2.70 2.1/2 - 8 2.5/8 67.00 5 - 0.70 18 4.30
6 - 32 UNC 36 2.85 3” - 8 3.1/4 82.50 5 - 0.75 18 4.25
6 - 40 UNF 33 2.95 Straight Pipe Taps - NPS 5.5 - 0.5 9 5.00
8 - 32 UNC 29 3.50 1/8 - 27 S 8.80 6 - 0.50 7/32 5.50
8 - 36 UNF 29 3.50 1/4 - 18 29/64 11.50 6 - 0.75 5 5.25
10 - 24 UNC 25 3.90 3/8 - 18 19/32 15.00 7 - 0.75 D 6.25
10 - 32 UNF 21 4.10 1/2 - 14 47/64 18.50 8 - 0.50 M 7.50
12 - 24 UNC 17 4.50 3/4 - 14 15/16 23.75 8 - 1.00 J 7.00
12 - 28 UNF 15 4.70 1 - 11.5 1.3/16 30.25 9 - 0.50 Q 8.50
1/4 - 20 UNC 7 5.10 1.1/4 - 11.5 1.33/64 38.50 9 - 1.00 O 8.00
1/4 - 28 UNF 3 5.50 1.1/2 - 11.5 1.3/4 44.50 10 - 0.50 3/8 9.50
5/16 - 18 UNC F 6.60 2” - 11.5 2.7/32 57.00 10 - 0.75 U 9.25
5/16 - 24 UNF I 6.90 I.S.O. Metric Coarse 10 - 1.00 T 9.00
3/8 - 16 UNC 5/16 8.00 1.6 - 0.35 3/64 1.25 10 - 1.25 11/32 8.75
3/8 - 24 UNF Q 8.50 1.7 - 0.35 55 1.35 11 - 1.00 X 10.00
7/16 - 14 UNC U 9.40 1.8 - 0.35 54 1.45 12 - 1.00 7/16 11.00
7/16 - 20 UNF W 9.90 2 - 0.40 1/16 1.60 12 - 1.25 27/64 10.75
1/2 - 13 UNC 27/64 10.80 2.2 - 0.45 50 1.75 12 - 1.50 Z 10.50
1/2 - 20 UNF 29/64 11.50 2.3 - 0.40 49 1.90 13 - 1.50 29/64 11.50
9/16 - 12 UNC 31/64 12.20 2.5 - 0.45 46 2.05 13 - 1.75 7/16 11.25
9/16 - 18 UNF 33/64 12.90 2.6 - 0.45 44 2.15 14 - 1.25 1/2 12.75
5/8 - 11 UNC 17/32 13.50 3 - 0.50 40 2.50 14 - 1.50 31/64 12.50
5/8 - 18 UNF 37/64 14.50 3.5 - 0.60 33 2.90 15 - 1.50 17/32 13.50
3/4 - 10 UNC 21/32 16.50 4 - 0.70 30 3.30 16 - 1.00 19/32 15.00
3/4 - 16 UNF 11/16 17.50 4.5 - 0.75 27 3.70 16 - 1.25 37/64 14.75
7/8 - 9 UNC 49/64 19.50 5.0 - 0.80 19 4.20 16 - 1.50 9/16 14.50
7/8 - 14 UNF 13/16 20.40 5.5 - 0.90 15 4.60 18 - 1.00 43/64 17.00
1 - 8 UNC 7/8 22.25 6 - 1.00 9 5.00 18 - 1.25 21/32 16.75
1 - 12 UNF 59/64 23.25 7 - 1.00 15/64 6.00 18 - 1.50 41/64 16.50
1 - 14 UNS 15/16 23.50 8 - 1.25 H 6.80 18 - 2.00 5/8 16.00
1.1/8 - 7 UNC 63/64 25.00 9 - 1.25 5/16 7.80 20 - 1.00 3/4 19.00
1.1/8 - 12 UNF 1.3/64 26.50 10 - 1.50 Q 8.50 20 - 1.50 47/64 18.50
1.1/4 - 7 UNC 1.7/64 28.00 11 - 1.50 3/8 9.50 20 - 2.00 45/64 18.00
1.1/4 - 12 UNF 1.11/64 29.50 12 - 1.75 Y 10.20 22 - 1.00 53/64 21.00
1.3/8 - 6 UNC 1.7/32 30.75 14 - 2.00 15/32 12.00 22 - 1.50 13/16 20.50
1.3/8 - 12 UNF 1.19/64 32.75 16 - 2.00 35/64 14.00 22 - 2.00 25/32 20.00
1.1/2 - 6 UNC 1.11/32 34.00 18 - 2.50 39/64 15.50 24 - 1.00 29/32 23.00
1.1/2 - 12 UNF 1.27/64 36.00 20 - 2.50 11/16 17.50 24 - 1.50 7/8 22.50
1.3/4 - 5 UNC 1.9/16 39.50 22 - 2.50 49/64 19.50 24 - 2.00 55/64 22.00
2” - 4.1/2 UNC 1.25/32 45.00 24 - 3.00 53/64 21.00 24 - 2.50 27/32 21.50

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