Drill Tap Chart

 

Tap and Drill Chart
(Recommended tap drill to use for 75% depth of thread)

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

* These Sizes Are Spark Plug Taps
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