Cox Machine Business Hours: Monday- Friday 7:00-5:00 Saturday 7:00-12:00
207-342-2267 Cox Machine, Rt 3 , 39 Belfast Augusta Rd., Searsmont, Maine 04973
Useful Information
Drill and Tap Charts - Inch & Metric
|
INCH TAP DRILL SIZES
Recommended tap drill sizes
(for approx. 75% thread)
|
INCH SIZES - NATIONAL COARSE
|
INCH SIZES - NATIONAL FINE
|
TAP DRILL
SIZE SIZE
|
TAP DRILL
SIZE SIZE
|
#1-64 #53
|
#0-80 3/64"
|
#2-56 #51
|
#1-72 #53
|
#3-48 5/64"
|
#2-64 #50
|
#4-40 #43
|
#3-56 #46
|
#5-40 #39
|
#4-48 #42
|
#6-32 #36
|
#5-44 #37
|
#8-32 #29
|
#6-40 #33
|
#10-24 #25
|
#8-36 #29
|
#12-24 #17
|
#10-32 #21
|
1/4-20 #7
|
#12-28 #15
|
5/16-18 F
|
1/4-28 #3
|
3/8-16 5/16
|
5/16-24 I
|
7/16-14 U
|
3/8-24 Q
|
1/2-13 27/64
|
7/16-20 W
|
9/16-12 31/64
|
1/2-20 29/64
|
5/8-11 17/32
|
9/16-18 33/64
|
3/4-10 21/32
|
5/8-18 37/64
|
7/8-9 49/64
|
3/4-16 11/16
|
1"-8 7/8
|
7/8-14 13/16
|
1-1/8-7 63/64
|
1"-14 15/16
|
1-1/4-7 1-7/64
|
1-1/8-12 1-3/64
|
1-1/2-6 1-11/32
|
1-1/4-12 1-11/64
|
1-3/4-5 1-35/64
|
1-1/2-12 1-27/64
|
2"-4-1/2 1-25/32
|
1-3/4-12 1-43/64
|
| |
2"-12 1-59/64
|
TAPER PIPE SIZES - NPT
|
STRAIGHT PIPE SIZES - NPS
|
TAP DRILL
SIZE SIZE
|
TAP DRILL
SIZE SIZE
|
1/8-27 R
|
1/8-27 S
|
1/4-18 7/16
|
1/4-18 29/64
|
3/8-18 37/64
|
3/8-18 19/32
|
1/2-14 23/32
|
1/2-14 47/64
|
3/4-14 59/64
|
3/4-14 15/16
|
1"-11-1/2 1-5/32
|
1"-11-1/2 1-3/16
|
1-1/4-11-1/2 1-1/2
|
1-1/4-11-1/2 1-33/64
|
1-1/2-11-1/2 1-47/64
|
1-1/2-11-1/2 1-3/4
|
2"-11-1/2 2-7/32
|
2"-11-1/2 2-7/32
|
2-1/2-8 2-5/8
|
2-1/2-8 2-21/32
|
3"-8 3-1/4
|
3"-8 3-9/32
|
3-1/2-8 3-3/4
|
3-1/2-8 3-25/32
|
4"-8 4-1/4
|
4"-8 4-9/32
|
| |
|
METRIC TAP DRILL SIZES
Recommended tap drill sizes (for approx. 75% thread)
|
METRIC COARSE SIZES
|
METRIC FINE SIZES
|
TAP DRILL
SIZE SIZE
|
TAP DRILL
SIZE SIZE
|
1mm x .25 .75mm
|
4 mm x .35 3.6mm
|
1.1 x .25 .85
|
4 x .5 3.5
|
1.2 x .25 .95
|
5 x .5 4.5
|
1.4 x .3 1.1
|
6 x .5 5.5
|
1.6 x .35 1.25
|
6 x .75 5.25
|
1.7 x .35 1.3
|
7 x .75 6.25
|
1.8 x .35 1.45
|
8 x .5 7.5
|
2 x .4 1.6
|
8 x .75 7.25
|
2.2 x .45 1.75
|
8 x 1 7
|
2.5 x .45 2.05
|
9 x 1 8
|
3 x .5 2.5
|
10 x .75 9.25
|
3.5 x.6 2.9
|
10 x 1 9
|
4 x .7 3.3
|
10 x 1.25 8.8
|
4.5 x .75 3.7
|
11 x 1 10
|
5 x.8 4.2
|
12 x .75 11.25
|
6 x 1 5
|
12 x 1 11
|
7 x 1 6
|
12 x 1.5 10.5
|
8 x1.25 6.8
|
14 x1 13
|
9 x 1.25 7.8
|
14 x 1.25 12.8
|
10 x 1.5 8.5
|
14 x 1.5 12.5
|
11 x 1.5 9.5
|
16 x1 15
|
12 x 1.75 10.2
|
16 x 1.5 14.5
|
14 x 2 12
|
18 x 1 17
|
16 x 2 14
|
18 x2 16
|
18 x 2.5 15.5
|
20 x 1 19
|
20 x 2.5 17.5
|
20 x 1.5 18.5
|
22 x 2.5 19.5
|
20 x2 18
|
24 x 3 21
|
22 x 1 21
|
27 x 3 24
|
22 x 1.5 20.5
|
30 x 3.5 26.5
|
22 x 2 20
|
33 x 3.5 29.5
|
24 x 1.5 22.5
|
36 x 4 32
|
24 x 2 22
|
39 x 4 35
|
26 x 1.5 24.5
|
| |
27 x 1.5 25.5
|
| |
27 x 2 25
|
| |
28 x 1.5 26.5
|
| |
30 x 1.5 28.5
|
| |
30 x 2 28
|
| |
33 x 2 31
|
| |
36 x 3 33
|
| |
39 x 3 36
|
Handy Helpers!
Tap Drill Sizes (inch) for a 75% Thread
In general, you can find the tap-drill for any size 60 degree thread, subtract
one pitch length from the major diameter.
Formula: Major Dia. minus One Pitch Length equals tap-drill size
English Example for 3/8-16 thread: .375 - .0625 = .3125 tap-drill (5/16)
Metric Example for M6 X 1 thread: 6mm - 1mm = 5mm tap-drill
|
|
