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Standard Tap and Drill Size Chart

Recommended tap drill to use for 75% depth to 3\8 inch

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To Tap This Size Screw Or Bolt: Use This Drill Bit: (Closest Fractional:) Decimal Inches
0-80 NF 3/64" 3/64" .0469
1-64 NC #53 - .0595
1-72 NF #53 1/16" .0595
2-56 NC #50 - .0700
2-64 NF #50 - .0700
3-48 NC #47 5/64" .0785
3-56 NF #45 - .0820
4-36 NS #44 - .0860
4-40 NC #43 3/32" .0890
4-48 NF #42 3/32" .0935
3mm-.060mm 2.5mm - .0984
1/8-40 NS #38 - .1015
5-40 NC #38 - .1015
5-44 NF #37 - .1040
6-32 NC #35 7/64" .1100
6-36 NS #34 - .1110
6-40 NF #33 - .1130
6-48 NS #31 - .1200
4mm-0.70mm 3.4mm - .1338
4mm-.075mm 3.4mm - .1338
8-32 NC #29 - .1360
8-36 NF #29 9/64" .1360
8-40 NS #28 - .1405
3/16-24 NS #26 - .1470
10-24 NC #25 5/32" .1495
3/16-32 NS #22 - .1570
10-32 NF #21 5/32" .1590
5mm-.090mm 4.2mm - .1653
5mm-.080mm 4.3mm - .1693
12-24 NC #16 11/64" .1770
12-28 NF #14 3/16" .1820
12-32 NEF #13 - .1850
14-20 NS #10 - .1935
1/4-20 NC #7 13/64" .2010
14-24 NS #7 - .2010
6mm-1.00mm 5.2mm - .2047
1/4-24 NS #4 - .2090
1/4-28 NF #3 7/32" .2130
1/4-32 NEF 7/32" 7/32" .2188
1/4-40 NS #1 - .2280
7mm-1.00mm 6.1mm 15/64" .2401
5/16-18 NC Ltr.F 17/64" .2570
8mm-1.25mm 6.9mm 17/64" .2716
5/16-24 NF Ltr.I - .2720
8mm-1.00mm 7.1mm - .2795
5/16-32 NEF 9/32" 9/32" .2812
9mm-1.25mm 7.9mm - .3110
3/8-16 NC 5/16" 5/16" .3125

 

To Tap This Size Screw Or Bolt: Use This Drill Bit: (Closest Fractional:) Decimal Inches
9mm-1.00mm 8.1mm - .3189
9mm-0.75mm 8.3mm - .3268
3/8-24 NF Ltr.Q 21/64" .3320
10mm-1.50mm 8.7mm - .3425
10mm-1.25mm 8.9mm 11/32" .3503
10mm-1.00mm* 9.1mm - .3583
7/16-14 NC Ltr.U 23/64" .3680
11mm-1.50mm 9.7mm - .3818
7/16-20 NF 25/64" 25/64" .3906
12mm-1.75mm 10.5mm - .4133
12mm-1.50mm 10.7mm 27/64" .4212
1/2-13 NC 27/64" 27/64" .4219
12mm-1.25mm* 10.9mm 27/64" .4291
1/2-20 NF 29/64" 29/64" .4531
1/2-24 NS 29/64" 29/64" .4531
14mm-2.00mm 12.2mm - .4803
9/16-12 NC 31/64" 31/64" .4844
14mm-1.50mm 12.7mm - .4999
14mm-1.25mm* 12.8mm - .5039
9/16-18 NF 33/64" 33/64" .5156
5/8-11 NC 17/32" 17/32" .5312
16mm-2.00mm 14.2mm 35/64" .5590
5/8-18 NF 37/64" 37/64" .5781
16mm-1.50mm 14.7mm - .5787
11/16-11 NS 19/32" 19/32" .5938
18mm-2.50mm 15.8mm 39/64" .5220
11/16-16 NS 5/8" 5/8" .6250
3/4-10 NC 21/32" 21/32" .6562
18mm-1.50mm* 16.8mm - .6614
3/4-16 NF 11/16" 11/16" .6875
20mm-2.50mm 17.8mm 11/16" .7008
7/8-9 NC 49/64" 49/64" .7656
7/8-14 NF 13/16" 13/16" .8125
22mm-1.50mm 20.9mm - .8228
7/8-18 NS* 53/64" 53/64" .8281
24mm-3.00mm 21.4mm 53/64" .8425
1.8 NC 7/8" 7/8" .8750
24mm-2.00mm 22.3mm - .8779
1.12 NF 59/64" 59/64" .9219
1-14 NS 15/16" 15/16" .9375
1 1/8-7 NC 63/64" 63/64" .9844
1 1/8-12 NF 1 3/64" 1 3/64" 1.0469
1 1/4-7 NC 1 7/64" 1 7/64" 1.1094
1 1/4-12 NF 1 11/64" 1 11/64" 1.1719
1 3/8-6 NC 1 7/32" 1 7/32" 1.2188
1 3/8-12 NF 1 19/64" 1 19/64" 1.2969
1 1/2-6 NC 1 11/32" 1 11/32" 1.3438
1 1/2"-12 NF 1 27/64" 1 27/64" 1.4219


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