Recommended Drill Sizes for Tapping
Tap NC |
Drill Inch |
Drill Metric |
| |
|
|
1-64 |
#53 |
1.55 |
2-56 |
#50 |
1.85 |
3-48 |
#47 |
2.10 |
4-40 |
#43 |
2.35 |
5-40 |
#38 |
2.65 |
6-32 |
#36 |
2.85 |
8-32 |
#29 |
3.50 |
10-24 |
#25 |
3.90 |
12-24 |
#16 |
4.50 |
1/4-20 |
#7 |
5.10 |
5/16-18 |
“F” |
6.60 |
3/8-16 |
5/16 |
8.00 |
7/16-14 |
“U” |
9.40 |
1/2-13 |
27/64 |
10.80 |
9/16-12 |
31/64 |
12.20 |
5/8-11 |
17/32 |
13.50 |
3/4-10 |
21/32 |
16.50 |
7/8-9 |
49/64 |
19.50 |
1″-8 |
7/8 |
22.25 |
1-1/8 7 |
63/64 |
25.00 |
1-1/4 7 |
1-7/64 |
28.00 |
1-3/8 6 |
1-7/32 |
30.75 |
1-1/2 6 |
1-11/32 |
34.00 |
1-3/4 5 |
1-9/16 |
39.50 |
2″ 4-1/2 |
1-25/32 |
45.00 |
|
Tap NF |
Drill Inch |
Drill Metric |
| |
|
|
0-80 |
3/64 |
1.25 |
1-72 |
#53 |
1.55 |
2-64 |
#50 |
1.90 |
3-56 |
#45 |
2.15 |
4-48 |
#42 |
2.40 |
5-44 |
#37 |
2.70 |
6-40 |
#33 |
2.95 |
8-36 |
#29 |
3.50 |
10-32 |
#21 |
4.10 |
12-28 |
#14 |
4.70 |
1/4-28 |
#3 |
5.50 |
5/16-24 |
“I” |
6.90 |
3/8-24 |
“Q” |
8.50 |
7/16-20 |
25/64 |
9.90 |
1/2-20 |
29/64 |
11.50 |
9/16-18 |
33/64 |
12.90 |
5/8-18 |
37/64 |
14.50 |
3/4-16 |
11/16 |
17.50 |
7/8-14 |
13/16 |
20.40 |
1″-12 |
59/64 |
23.25 |
1″-14NS |
15/16 |
23.50 |
1-1/8 12 |
1-3/64 |
26.50 |
1-1/4 12 |
1-11/64 |
29.50 |
1-3/8 12 |
1-19/64 |
32.75 |
1-1/2 12 |
1-27/64 |
36.00 |
|
Tap MM |
Drill Inch |
Drill Metric |
| |
|
|
M1.0 X 0.25 |
#68 |
0.75 |
M1.1 X 0.25 |
#65 |
0.85 |
M1.2 X 0.25 |
#62 |
0.95 |
M1.4 X 0.30 |
#57 |
1.10 |
M1.6 X 0.35 |
3/64 |
1.25 |
M1.8 X 0.35 |
#53 |
1.45 |
M2.0 X 0.40 |
1/16 |
1.60 |
M2.2 X 0.45 |
#50 |
1.75 |
M2.5 X 0.45 |
#46 |
2.05 |
M3.0 X 0.50 |
#40 |
2.50 |
M3.5 X 0.60 |
#32 |
2.90 |
M4.0 X 0.70 |
#30 |
3.30 |
M4.5 X 0.75 |
#26 |
3.70 |
M5.0 X 0.80 |
#19 |
4.20 |
M6.0 X 1.00 |
#9 |
5.00 |
M7.0 X 1.00 |
15/64 |
6.00 |
M8.0 X 1.25 |
17/64 |
6.80 |
M9.0 X 1.25 |
5/16 |
7.80 |
M10 X 1.50 |
“Q” |
8.50 |
M11 X 1.50 |
“V” |
9.50 |
M12 X 1.75 |
“Y” |
10.20 |
M14 X 2.00 |
15/32 |
12.00 |
M16 X 2.00 |
35/64 |
14.00 |
M18 X 2.50 |
39/64 |
15.50 |
M20 X 2.50 |
11/16 |
17.50 |
M22 X 2.50 |
49/64 |
19.50 |
M24 X 3.00 |
53/64 |
21.00 |
M27 X 3.00 |
61/64 |
24.00 |
M30 X 3.50 |
1-3/64 |
26.50 |
M33 X 3.50 |
1-11/64 |
29.50 |
M36 X 4.00 |
1-1/4 |
32.00 |
M39 X 4.00 |
1-3/8 |
35.00 |
M42 X 4.50 |
1-31/64 |
37.50 |
M45 X 4.50 |
1-19/32 |
40.50 |
M48 X 5.00 |
1-45/64 |
43.00 |
M52 X 5.00 |
1-55/64 |
47.00 |
M56 X 5.50 |
1-63/64 |
50.50 |
|
Tap MF/MS |
Drill Inch |
Drill Metric |
| |
|
|
MF3.0 X 0.35 |
#37 |
2.65 |
MF3.5 X 0.35 |
1/8 |
3.15 |
MF4.0 X 0.50 |
#28 |
3.50 |
MF4.5 X 0.50 |
#21 |
4.00 |
MF5.0 X 0.50 |
#16 |
4.50 |
MF6.0 X 0.75 |
#5 |
5.20 |
MF7.0 X 0.75 |
“D” |
6.20 |
MF8.0 X 1.00 |
“J” |
7.00 |
MS8.0 X 0.75 |
“L” |
7.20 |
MS9.0 X 1.00 |
“O” |
8.00 |
MF10 X 1.25 |
11/32 |
8.80 |
MS10 X 1.00 |
“T” |
9.00 |
MS10 X 0.75 |
“U” |
9.20 |
MS11 X 0.75 |
“Y” |
10.20 |
MS12 X 1.50 |
“Z” |
10.50 |
MF12 X 1.25 |
27/64 |
10.80 |
MS12 X 1.00 |
7/16 |
11.00 |
MF14 X 1.50 |
31/64 |
12.50 |
MS14 X 1.25 |
33/64 |
12.80 |
MF16 X 1.50 |
9/16 |
14.50 |
MS16 X 1.00 |
19/32 |
15.00 |
MF18 X 1.50 |
41/64 |
16.50 |
MS18 X 1.00 |
43/64 |
17.00 |
MF20 X 1.50 |
23/32 |
18.50 |
MS20 X 1.00 |
3/4 |
19.00 |
MF22 X 1.50 |
13/16 |
20.50 |
MF24 X 2.00 |
55/64 |
22.00 |
MS24 X 1.50 |
57/64 |
22.50 |
MS25 X 1.50 |
59/64 |
23.50 |
MF27 X 2.00 |
63/64 |
25.00 |
MF30 X 2.00 |
1-7/64 |
28.00 |
MS32 X 1.50 |
1-13/64 |
30.50 |
MF33 X 2.00 |
1-7/32 |
31.00 |
MF36 X 3.00 |
1-19/64 |
33.00 |
MF39 X 3.00 |
1-27/64 |
36.00 |
|
Tap
NPT |
Drill
Inch |
Drill
Metric |
| |
|
|
1/16-27 |
“D” |
6.30 |
1/8-27 |
“Q” |
8.50 |
1/4-18 |
7/16 |
11.10 |
3/8-18 |
9/16 |
14.70 |
1/2-14 |
45/64 |
18.25 |
3/4-14 |
29/32 |
23.40 |
1″ 11-1/2 |
1-9/64 |
29.40 |
1-1/4 11-1/2 |
1-31/64 |
38.10 |
1-1/2 11-1/2 |
1-47/64 |
44.00 |
2″ 11-1/2 |
2-13/64 |
56.30 |
|
Tap
NPS |
Drill
Inch |
Drill
Metric |
| |
|
|
1/16-27 |
1/4 |
6.80 |
1/8-27 |
11/32 |
9.10 |
1/4-18 |
7/16 |
11.90 |
3/8-18 |
37/64 |
15.25 |
1/2-14 |
23/32 |
19.00 |
3/4-14 |
59/64 |
23.75 |
1″ 11-1/2 |
1-5/32 |
30.00 |
1-1/4 11-1/2 |
1-33/64 |
39.50 |
1-1/2 11-1/2 |
1-3/4 |
45.50 |
2″ 11-1/2 |
2-7/32 |
62.00 |
|
Tap
BSW |
Drill
MM |
| |
|
1/8-40 |
2.55 |
5/32-32 |
3.20 |
3/16-24 |
3.70 |
7/32-24 |
4.50 |
1/4-20 |
5.10 |
5/16-18 |
6.50 |
3/8-16 |
7.90 |
7/16-14 |
9.30 |
1/2-12 |
10.50 |
9/16-12 |
12.10 |
5/8-11 |
13.50 |
11/16-10 |
15.00 |
3/4-10 |
16.25 |
7/8-9 |
19.25 |
1″-8 |
22.00 |
1-1/8 7 |
24.75 |
1-1/4 7 |
28.00 |
1-1/2 6 |
33.50 |
1-3/4 5 |
39.00 |
2″ 4-1/2 |
44.50 |
|
Tap
BSF |
Drill
MM |
| |
|
3/16-32 |
4.00 |
7/32-28 |
4.60 |
1/4-26 |
5.30 |
9/32-26 |
6.10 |
5/16-22 |
6.80 |
3/8-20 |
8.30 |
7/16-18 |
9.70 |
1/2-16 |
11.10 |
9/16-16 |
12.70 |
5/8-14 |
14.00 |
11/16-14 |
15.50 |
3/4-12 |
16.75 |
7/8-11 |
19.75 |
1″-10 |
22.75 |
1-1/8 9 |
25.50 |
1-1/4 9 |
28.50 |
1-3/8 8 |
31.50 |
1-1/2 8 |
34.50 |
1-3/4 7 |
40.50 |
2″-7 |
47.00 |
|
Tap
BSPT |
Drill
Inch |
| |
|
1/8-28 |
8.40 |
1/4-19 |
11.20 |
3/8-19 |
14.75 |
1/2-14 |
18.25 |
3/4-14 |
23.75 |
1″-11 |
30.00 |
1-1/4 11 |
38.50 |
1-1/2 11 |
44.50 |
2″-11 |
56.00 |
2-1/2 11 |
71.00 |
Tap
BSP |
Drill
Inch |
| |
|
1/8-28 |
8.60 |
1/4-19 |
11.50 |
3/8-19 |
15.00 |
1/2-14 |
18.75 |
5/8-14 |
20.75 |
3/4-14 |
24.25 |
7/8-14 |
28.00 |
1″-11 |
30.40 |
1-1/2 11 |
45.00 |
2″-11 |
56.75 |
|
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