TM 5-3810-307-24-1-2
Tap-Drill Chart - U.S. Customary & Metric
NOTE ON SELECTING TAP-DRILL SIZES: The tap drill sizes shown on this card give the theoretical tap drill size for approximately
60% and 75% of full thread depth. Generally, it is recommended that drill sizes be selected in the 60% range as these sizes will
provide about 90% of the potential holding power. Drill sizes in the 75% range are recommended for shallow hole tapping (less than
1 1/2 times the hole diameter) in soft metals and mild steel.
Tap Size
Drill
Tap Size
Drill
Tap Size
Drill
Tap Size
Drill
60 %
75 %
Size
60 %
75 %
Size
60 %
75 %
Size
60 %
75 %
Size
48
4.40mm
7.50mm
13.25mm
1.95mm
12-24
16
19/64
5/8-11
17/32
5/64
4.50mm
7.60mm
M15x1.5
13.50mm
3-48
47
15
N
M15x1.5
13.75mm
2.00mm
M5.5x.9
4.60mm
7.70mm
5/8-11
35/64
M2.5x.45
2.05mm
12-24
12-28
14
M9x1.25
7.75mm
M16x2
14.00mm
46
13
7.80mm
14.25mm
3-48
3056
45
4.70mm
7.90mm
5/8-18
9/16
2.10mm
M5.5x.9
4.75mm
3/8-16
5/16
M16x2
M16x1.5
14.50mm
M2.5x.45
M2.6x.45
2.15mm
12-28
3/16
M9x1.25
M9x1
8.00mm
5/8-18
37/64
3-56
4-36
44
12
O
14.75mm
2.20mm
4.80mm
8.10mm
M16x1.5
15.00mm
M2.6x.45
2.25mm
11
M9x1
8.20mm
19.32
4-36
4-40
43
4.90mm
P
15.25mm
2.30mm
10
8.25mm
39/64
2.35mm
9
8.30mm
M17x1.5
15.50mm
4-40
4-48
42
M6x1
5.00mm
3/8-16
1/8-27NPT 21/64
M17x1.5
M18x2.5
15.75mm
3/32
8
8.40mm
5/8
M3x.6
2.40mm
5.10mm
3/8-24
Q
M18x2.5
M18x2
16.00mm
4-48
41
1/4-20
7
M10x1.5
8.50mm
M18x2
16.25mm
2.45mm
13/64
8.60mm
3/4-10
41/64
40
6
R
M18x1.5
16.50mm
M3x.6
M3x.5
2.50mm
M6x1
5.20mm
3/8-24
8.70mm
3/4-10
M19x2.5
21/32
39
5
1/8-27NPT
11/32
M18x1.5
16.75mm
5-40
38
M6x.75
5.25mm
M10x1.25 8.75mm
M19x2.5
17.00mm
M3x.5
2.60mm
5.30mm
M10x1.5
8.80mm
43/64
5-40
5-44
37
1/4-20
4
S
17.25mm
2.70mm
M6x.75
5.40mm
8.90mm
3/4-16
3/4-16
11/16
5-44
6-32
36
1/4-28
3
M10x1.25 M10x1
9.00mm
M20x2.5
17.50mm
2.75mm
5.50mm
T
17.75mm
7/64
7/32
9.10mm
45/64
35
5.60mm
23/64
M20x2.5
M20x2
18.00mm
2.80mm
1/4-28
2
M10x1
9.20mm
M20x2
18.25mm
34
5.70mm
9.30mm
23/32
6-32
6-40
33
5.75mm
7/16-14
U
M20x1.5
18.50mm
M3.5x6
2.90mm
1
9.40mm
47/64
32
5.80mm
M11x1.5
9.50mm
M20x1.5
18.75mm
M3.5x6
3.00mm
5.90mm
3/8
19.00mm
6-40
31
A
V
3/4
3.10mm
15/64
9.60mm
19.25mm
1/8
M7x1
6.00mm
9.70mm
7/8-9
49/64
3.20mm
B
9.75mm
M22x2.5
19.50mm
M4x.75
3.25mm
6.10mm
M11x1.5
9.80mm
7/8-9
25/32
30
C
7/16-14
W
19.75mm
M4x.7
3.30mm
M7x1
6.20mm
9.90mm
M22x2.5
M22x2
20.00mm
M4x.75
3.40mm
D
7/16-20
25/64
7/8-14
51/64
M4x.7
8-32
29
M7x.75
6.25mm
10.00mm
M22x2
20.25mm
3.50mm
6.30mm
7/16-20
X
M22x1.5
20.50mm
8-36
28
E
M12x1.75 10.20mm
7/8-14
13/16
8-32
9/64
1/4
Y
20.75mm
3.60mm
M7x.75
6.40mm
13/32
M22x1.5
M24x3
21.00mm
8-36
27
6.50mm
Z
53/64
3.70mm
5/16-18
F
M12x1.75 M12x1.5
10.50mm
21/25mm
26
6.60mm
1/2-13
27/64
27/32
M4.5x.75
3.75mm
G
M12x1.5
M12x1.25 10.75mm
M24x3
21.50mm
10-24
25
6.70mm
M12x1.25
11.00mm
21.75mm
3.80mm
17/64
1/2-13
7/16
55/64
24
M8x1.25
6.75mm
1/4-18NPT
M24x2
22.00mm
M4.5x.75
3.90mm
5/16-18
H
11.25mm
1"-8
7/8
23
6.80mm
11.50mm
M24x2
22.25mm
5/32
6.90mm
29/64
M24x1.5
22.50mm
10-24
22
5.16-24
I
11.75mm
1"-8
57/64
M5x1
4.00mm
M8x1.25
M8x1
7.00mm
11.50mm
M24x1.5
22.75mm
10-32
21
J
1/2-20
29/64
M25x2
23.00mm
20
7.10mm
9/16-12
15/32
1"-12
29/32
M5x.9
4.10mm
5/16-24
K
M14x2
12.00mm
M25x2
23.25mm
M5x1
M5x.8
4.20mm
9/32
12.25mm
1"x12
1"-14
59/64
10-32
19
M8x1
7.20mm
9/16-12
31/64
M25x1.5
23.50mm
M5x.9
4.25mm
7.25mm
M14x2
M14x1.5
12.50mm
M20x1.5
23.75mm
M5x.8
4.30mm
7.30mm
9/16-18
1/2
1"-14
15/16
18
L
M14x1.5
M14x1.25 12.75mm
11/64
7.40mm
M14x1.25
13.00mm
17
M
9/16-18
33/64
V-14 Change-1
