Fillable Printable Tap Drill and Thread Height Chart
Fillable Printable Tap Drill and Thread Height Chart
Tap Drill and Thread Height Chart
Thread Ma
j
or Threads
p
er
Tap Drill Tap Tap Drill Theoretical
%
Size Diameter Inch
(
TPI
)
Range Drill Decimal of Thread
0-80 0.0600 80 0.0465 - 0.0514
3/64 0.0469 80.7%
1-64 0.0730 64 0.0561 - 0.0623
53 0.0595 66.5%
53 0.0595 74.8%
1/16 0.0625 58.2%
52 0.0635 52.7%
51 0.0670 81.9%
50 0.0700 69.0%
49 0.0730 56.0%
50 0.0700 78.8%
49 0.0730 64.0%
48 0.0760 85.0%
5/64 0.0781 77.2%
47 0.0785 75.8%
2mm 0.0787 75.0%
46 0.0810 66.5%
45 0.0820 62.8%
46 0.0810 77.6%
45 0.0820 73.3%
44 0.0860 56.0%
44 0.0860 80.1%
43 0.0890 70.8%
42 0.0935 57.0%
3/32 0.0937 56.4%
42 0.0935 68.4%
3/32 0.0937 67.6%
41 0.0960 59.1%
40 0.0980 83.1%
39 0.0995 78.5%
38 0.1015 72.4%
37 0.1040 64.7%
38 0.1015 79.6%
37 0.1040 71.1%
36 0.1065 62.7%
37 0.1040 83.8%
36 0.1065 77.6%
7/64 0.1094 70.5%
35 0.1100 69.0%
34 0.1110 66.5%
33 0.1130 61.6%
34 0.1110 83.1%
33 0.1130 77.0%
32 0.1160 67.7%
3mm 0.1181 61.3%
8-32 0.1640 32 0.1300 - 0.1389
29 0.1360 69.0%
29 0.1360 77.6%
28 0.1405 65.1%
9/64 0.1406 64.8%
26 0.1470 79.4%
25 0.1495 74.8%
24 0.1520 70.2%
23 0.1540 66.5%
24 0.1520 81.9%
23 0.1540 77.6%
5/32 0.1562 72.9%
400.13806-40
0.190010-28
240.190010-24
360.16408-36
560.09903-56
28
5-40
480.11204-48
400.11204-40
0.08602-56
320.13806-32
440.12505-44
400.1250
720.07301-72
480.09903-48
2-64 0.0860 64
56
0.0979 - 0.1062
0.0894 - 0.0968
0.0849 - 0.0939
0.0797 - 0.0865
0.0764 - 0.0845
0.0691 - 0.0753
0.0667 - 0.0737
0.0580 - 0.0635
0.1510 - 0.1600
0.1450 - 0.1555
0.1340 - 0.1416
0.1110 - 0.1186
0.1040 - 0.1140
0.1004 - 0.1079
Tap Drill & Thread Height Chart
This chart disp lays a var ie ty of UN Thre ad size s, the ir likely Tap Dr ills and the resulting Theoretical
Thread Height Per centag e . This perce ntag e is thoeretical as holes are often drilled slightly oversized.
Typically, tap drills are selected to result in a 60% - 75% thread height. There is neglible increased
strength in threads with more than 60% thread height and larger tap drills are preferred for their
strength and speed.
Thread Ma
j
or Threads
p
er
Tap Drill Tap Tap Drill Theoretical
%
Size Diameter Inch
(
TPI
)
Range Drill Decimal of Thread
22 0.1570 71.1%
4mm 0.1575 70.1%
5/32 0.1562 83.3%
22 0.1570 81.3%
4mm 0.1575 80.1%
21 0.1590 76.4%
20 0.1610 71.4%
20 0.1610 80.4%
19 0.1660 66.5%
10-40 0.1900 40 0.1630 - 0.1690
19 0.1660 73.9%
18 0.1695 75.8%
11/64 0.1719 66.9%
11/64 0.1719 78.0%
17 0.1730 73.3%
11/64 0.1719 81.5%
17 0.1730 79.4%
16 0.1770 72.1%
15 0.1800 66.5%
16 0.1770 84.1%
15 0.1800 77.6%
14 0.1820 73.3%
13 0.1850 66.8%
14 0.1820 83.8%
13 0.1850 76.4%
3/16 0.1875 70.2%
12 0.1890 66.5%
3/16 0.1875 79.0%
12 0.1890 74.8%
11 0.1910 69.3%
12 0.1890 83.1%
11 0.1910 77.0%
10 0.1935 69.3%
10 0.1935 83.1%
9 0.1960 73.9%
5mm 0.1968 70.9%
8 0.1990 73.3%
7 0.2010 64.7%
9 0.1960 83.1%
5mm 0.1968 81.9%
8 0.1990 78.5%
7 0.2010 75.4%
13/64 0.2031 72.2%
6 0.2040 70.8%
5 0.2055 68.5%
5 0.2055 82.2%
4 0.2090 75.8%
3 0.2130 68.4%
3 0.2130 76.9%
7/32 0.2187 65.1%
3 0.2130 79.8%
7/32 0.2187 67.5%
7/32 0.2187 77.1%
2 0.2210 71.4%
1 0.2280 54.2%
1/4-36 0.2500 36 0.2200 - 0.2260
2 0.2210 80.4%
1/4-40 0.2500 40 0.2230 - 0.2290
1 0.2280 67.7%
1/4-48 0.2500 48 0.2270 - 0.2320
1 0.2280 81.3%
A 0.2340 69.0%
15/64 0.2344 67.3%
F 0.2570 76.9%
G 0.2610 71.4%
G 0.2610 79.3%
17/64 0.2656 72.2%
H 0.2660 71.6%
I 0.2720 74.8%
7mm 0.2756 68.2%
I 0.2720 84.2%
7mm 0.2756 76.7%
24
1/4-28
200.25001/4-20
270.25001/4-27
560.25001/4-56
0.25001/4-24
320.25001/4-32
280.2500
200.31255/16-20
180.31255/16-18
270.31255/16-27
240.31255/16-24
560.190010-56
480.190010-48
280.216012-28
240.216012-24
0.216012-40
360.216012-36
320.216012-32
560.216012-56
480.216012-48
40
360.190010-36
320.190010-32
0.1930 - 0.1980
0.1890 - 0.1950
0.1860 - 0.1920
0.1820 - 0.1895
0.1770 - 0.1857
0.1710 - 0.1807
0.1710 - 0.1750
0.1670 - 0.1720
0.1600 - 0.1660
0.1560 - 0.1640
0.2720 - 0.2810
0.2670 - 0.2754
0.2580 - 0.2680
0.2520 - 0.2630
0.2310 - 0.2350
0.2160 - 0.2229
0.2110 - 0.2190
0.2100 - 0.2190
0.2050 - 0.2150
0.1960 - 0.2067
0.1970 - 0.2010
Thread Ma
j
or Threads
p
er
Tap Drill Tap Tap Drill Theoretical
%
Size Diameter Inch
(
TPI
)
Range Drill Decimal of Thread
J 0.2770 73.8%
K 0.2810 65.5%
7mm 0.2756 79.5%
J 0.2770 76.5%
K 0.2810 77.6%
9/32 0.2812 77.1%
5/16-36 0.3125 36 0.2820 - 0.2890
Special
5/16-40 0.3125 40 0.2850 - 0.2910
L 0.2900 69.3%
L 0.2900 83.1%
M 0.2950 64.7%
5/16 0.3125 77.0%
8mm 0.3150 73.9%
O 0.3160 72.7%
8mm 0.3150 83.1%
O 0.3160 81.8%
P 0.3230 72.1%
P 0.3230 80.1%
21/64 0.3281 72.2%
3/8-24 0.3750 24 0.3300 - 0.3372
Q 0.3320 79.4%
R 0.3390 74.8%
11/32 0.3437 65.1%
3/8-28 0.3750 28 0.3360 - 0.3426
R 0.3390 77.6%
3/8-32 0.3750 32 0.3410 - 0.3469
11/32 0.3437 77.1%
3/8-36 0.3750 36 0.3450 - 0.3520
S 0.3480 74.8%
3/8-40 0.3750 40 0.3480 - 0.3540
S 0.3480 83.1%
7/16-14 0.4375 14 0.3600 - 0.3717
U 0.3680 74.9%
3/8 0.3750 77.0%
V 0.3770 74.5%
V 0.3770 83.8%
W 0.3860 71.4%
W 0.3860 79.3%
25/64 0.3906 72.2%
10mm 0.3937 80.9%
X 0.3970 74.8%
X 0.3970 84.2%
Y 0.4040 69.6%
7/16-28 0.4375 28 0.3990 - 0.4051
Y 0.4040 72.2%
Y 0.4040 82.5%
13/32 0.4062 77.1%
Z 0.4130 80.4%
27/64 0.4219 72.1%
1/2-13 0.5000 13 0.4170 - 0.4284
27/64 0.4219 78.2%
11mm 0.4331 72.1%
7/16 0.4375 67.4%
11mm 0.4331 82.4%
7/16 0.4375 77.0%
1/2-18 0.5000 18 0.4400 - 0.4530
Special
1/2-20 0.5000 20 0.4460 - 0.4537
29/64 0.4531 72.2%
1/2-24 0.5000 24 0.4550 - 0.4650
Special
1/2-27 0.5000 27 0.4600 - 0.4690
15/32 0.4687 65.1%
1/2-28 0.5000 28 0.4610 - 0.4676
Special
1/2-32 0.5000 32 0.4660 - 0.4719
15/32 0.4687 77.1%
9/16-12 0.5625 12 0.4720 - 0.4843
12mm 0.4724 83.2%
9/16-14 0.5625 14 0.4850 - 0.5010
1/2 0.5000 67.4%
9/16-16 0.5625 16 0.4950 - 0.5040
1/2 0.5000 77.0%
9/16-18 0.5625 18 0.5020 - 0.5106
Special
13mm 0.5118 78.1%
33/64 0.5156 72.2%
9/16-24 0.5625 24 0.5170 - 0.5244
Special
9/16-27 0.5625 27 0.5220 - 0.5310
Special
9/16-28 0.5625 28 0.5240 - 0.5301
Special
9/16-32 0.5625 32 0.5290 - 0.5344
17/32 0.5312 77.1%
5/8-11 0.6250 11 0.5270 - 0.5391
17/32 0.5312 79.4%
5/8-12 0.6250 12 0.5350 - 0.5463
Special
14mm 0.5512 79.5%
9/16 0.5625 67.4%
5/8-16 0.6250 16 0.5570 - 0.5662
9/16 0.5625 77.0%
5/8-18 0.6250 18 0.5650 - 0.5730
Special
120.50001/2-12
0.56259/16-20
160.50001/2-16
14
14
0.50001/2-14
200.37503/8-20
270.37503/8-27
0.4375
0.62505/8-14
20
160.43757/16-16
200.43757/16-20
187/16-18
320.43757/16-32
270.43757/16-27
240.43757/16-24
180.37503/8-18
320.31255/16-32
280.31255/16-28
160.37503/8-16
480.31255/16-48 0.2900 - 0.2950
0.2790 - 0.2847
0.2740 - 0.2807
0.5480 - 0.5640
0.5080 - 0.5162
0.4320 - 0.4419
0.4230 - 0.4380
0.4100 - 0.4223
0.3350 - 0.3440
0.3210 - 0.3297
0.3150 - 0.3280
0.3070 - 0.3182
0.4040 - 0.4094
0.3970 - 0.4060
0.3920 - 0.4020
0.3830 - 0.3916
0.3770 - 0.3900
0.3700 - 0.3800
Thread Ma
j
or Threads
p
er
Tap Drill Tap Tap Drill Theoretical
%
Size Diameter Inch
(
TPI
)
Range Drill Decimal of Thread
5/8-20 0.6250 20 0.5710 - 0.5787
37/64 0.5781 72.2%
5/8-24 0.6250 24 0.5800 - 0.5869
Special
15mm 0.5906 71.5%
19/32 0.5937 65.1%
5/8-28 0.6250 28 0.5860 - 0.5926
15mm 0.5906 74.1%
5/8-32 0.6250 32 0.5910 - 0.5969
19/32 0.5937 77.1%
11/16-12 0.6875 12 0.5970 - 0.6085
Special
11/16-16 0.6875 16 0.6200 - 0.6284
5/8 0.6250 77.0%
11/16-20 0.6875 20 0.6330 - 0.6412
41/64 0.6406 72.2%
11/16-24 0.6875 24 0.6420 - 0.6494
Special
11/16-28 0.6875 28 0.6490 - 0.6551
Special
11/16-32 0.6875 32 0.6540 - 0.6594
21/32 0.6562 77.1%
3/4-10 0.7500 10 0.6420 - 0.6545
Special
3/4-12 0.7500 12 0.6600 - 0.6707
17mm 0.6693 74.5%
3/4-14 0.7500 14 0.6730 - 0.6880
11/16 0.6875 67.4%
3/4-16 0.7500 16 0.6820 - 0.6908
11/16 0.6875 77.0%
3/4-18 0.7500 18 0.6900 - 0.7030
Special
3/4-20 0.7500 20 0.6960 - 0.7037
45/64 0.7031 72.2%
3/4-24 0.7500 24 0.7050 - 0.7150
18mm 0.7087 76.3%
3/4-28 0.7500 28 0.7110 - 0.7176
Special
3/4-32 0.7500 32 0.7160 - 0.7219
23/32 0.7187 77.1%
13/16-12 0.8125 12 0.7220 - 0.7329
Special
19mm 0.7480 79.4%
3/4 0.7500 77.0%
13/16-20 0.8125 20 0.7580 - 0.7662
49/64 0.7656 72.2%
13/16-28 0.8125 28 0.7740 - 0.7801
Special
13/16-32 0.8125 32 0.7790 - 0.7844
25/32 0.7812 77.1%
7/8-9 0.8750 9 0.7550 - 0.7681
49/64 0.7656 75.8%
25/32 0.7812 72.2%
20mm 0.7874 67.4%
7/8-12 0.8750 12 0.7850 - 0.7948
Special
7/8-14 0.8750 14 0.7980 - 0.8068
Special
7/8-16 0.8750 16 0.8070 - 0.8158
13/16 0.8125 77.0%
7/8-18 0.8750 18 0.8150 - 0.8280
21mm 0.8268 66.8%
21mm 0.8268 74.2%
53/64 0.8281 72.2%
7/8-24 0.8750 24 0.8300 - 0.8400
Special
7/8-27 0.8750 27 0.8350 - 0.8440
27/32 0.8437 65.1%
7/8-28 0.8750 28 0.8360 - 0.8426
Special
7/8-32 0.8750 32 0.8410 - 0.8469
27/32 0.8437 77.1%
15/16-12 0.9375 12 0.8470 - 0.8575
Special
15/16-16 0.9375 16 0.8700 - 0.8783
7/8 0.8750 77.0%
15/16-20 0.9375 20 0.8830 - 0.8912
57/64 0.8906 72.2%
15/16-28 0.9375 28 0.8990 - 0.9051
Special
23mm 0.9055 78.8%
29/32 0.9062 77.1%
22mm 0.8661 82.5%
7/8 0.8750 77.0%
23mm 0.9055 72.7%
29/32 0.9062 72.2%
1-12 1.0000 12 0.9100 - 0.9198
Special
1-14 1.0000 14 0.9230 - 0.9315
Special
1-16 1.0000 16 0.9320 - 0.9408
15/16 0.9375 77.0%
1-18 1.0000 18 0.9400 - 0.9530
24mm 0.9449 76.4%
1-20 1.0000 20 0.9460 - 0.9537
61/64 0.9531 72.2%
1-24 1.0000 24 0.9550 - 0.9650
Special
1-27 1.0000 27 0.9600 - 0.9690
31/32 0.9687 65.1%
1-28 1.0000 28 0.9610 - 0.9676
Special
1-32 1.0000 32 0.9660 - 0.9719
31/32 0.9687 77.1%
160.812513/16-16
0.937515/16-32
200.87507/8-20
100.87507/8-10
101.00001-10
81.00001-8
32
270.62505/8-27
0.8920 - 0.9130
0.8650 - 0.8797
0.9040 - 0.9094
0.8210 - 0.8287
0.7670 - 0.7880
0.7450 - 0.7533
0.5850 - 0.5940
