Tag: Tap

National Pipe Thread (NPT) Tap Drill Size

 

Standard NPT Tap Drill Sizes
NPT Size
 Tap Drill Size (in.)
Decimal Equivalent (in.)
1/16 – 27
“C”
0.242
1/8 – 27
“Q” 
0.332
1/4 – 18
7/16
0.438
3/8 – 18
9/16
0.562
1/2 – 14
45/64
0.703
3/4 – 14
29/32
0.906
1.0 – 11•1/2
1•9/64
1.141
1•1/4 – 11•1/2
1•31/64
1.484
1•1/2 – 11•1/2
1•23/32
1.719
2.0 – 11•1/2
2•3/16
2.188
2•1/2 – 8
2•39/64
2.609
3.0 – 8
3•15/64
3.234
 
Metric Tap Drill Sizes
Standard UNC Tap Drill Sizes
Standard UNF Tap Drill Sizes

Metric Thread – Tap Drill / Clearance Drill


Metric Tap Drill Chart
Tap size Major
Dia (mm)		 Threads
per 		Tap Drill
(mm)		 Tap Drill
(inch)		 Clearance
(mm)		 Clearance
(inch)
M1.6×0.35 1.6 0.35 1.25 #55 1.8 #49
M2x0.4 2.0 0.40 1.60 #52 2.4 #41
M2.5×0.45 2.5 0.45 2.05 #46 2.9 #32
M3x.05 3.0 0.50 2.50 #39 3.4 #29
M3.5×0.6 3.5 0.60 2.90 #32 3.9 #23
M4x0.7 4.0 0.70 3.30 #30 4.5 #16
M5x0.8 5.0 0.80 4.20 #19 5.5 7/32
M6x1 6.0 1.00 5.0 #8 6.6 G
M8x1.25 8.0 1.25 6.8 H 9.0 T
M8x1 8.0 1.00 7.0 J 9.0 T
M10x1.5 10.0 1.50 8.5> R 12.0 31/64
M10x1.25 10.0 1.25 8.8 11/32 12.0 31/64
M12x1.75 12.0 1.75 10.2 13/32 14.0 35/64
M12x1.25 12.0 1.25 10.8 27/64 14.0 35/64
M14x2 14.0 2.00 12.0 15/32 16.0 5/8
M14x1.5 14.0 1.5 12.5 1/2 16.0 5/8
M16x2 16.0 2.00 14.0 35/64 18.0 45/64
M16x1.5 16.0 1.50 14.5 37/64 18.0 45/64
M18x2.5 18.0 2.50 15.5 39/64 20.0 51/64
M18x1.5 18.0 1.50 16.5 21/32 20.0 51/64
M20x2.5 20.0 2.50 17.5 11/16 22.0 7/8
M20x1.5 20.0 1.50 18.5 47/64 22.0 7/8
M22x2.5 22.0 2.50 19.5 49/64 25.0 1
M22x1.5 22.0 1.50 20.5 13/16 25.0 1
M24x3 24.0 3.00 21.0 53/64 27.0 1-5/64
M24x2 24.0 2.00 22.0 7/8 27.0 1-5/64
M27x3 27.0 3.00 24.0 15/16 30.0 1-3/16
M27x2 27.0 2.0 25.0 1 30.0 1-3/16
 
Standard UNC Tap Drill Sizes
Standard UNF Tap Drill Sizes
Standard NPT Tap Drill Sizes

Tap Drill Size – UNF


INCH SIZES – NATIONAL FINE
TAP SIZE DRILL SIZE
#1-72 #53
#2-64 #50
#3-56 #46
#4-48 #42
#5-44 #37
#6-40 #33
#8-36 #29
#10-32 #21
#12-28 #15
1/4-28 #3
5/16-24 I
3/8-24 Q
7/16-20 W
1/2-20 29/64
9/16-18 33/64
5/8-18 37/64
3/4-16 11/16
7/8-14 13/16
1″-12 15/16
1-1/8-12 1-3/64
1-1/4-12 1-11/64
1-1/2-12 1-27/64
1-3/4-12 1-43/64
2″-12 1-59/64
 
Metric Tap Drill Sizes
Standard UNC Tap Drill Sizes
Standard NPT Tap Drill Sizes

Tap Drill Size – UNC


INCH SIZES – NATIONAL COARSE
TAP SIZE DRILL SIZE
#0-80 3/64″
#1-64 #53
#2-56 #51
#3-48 5/64″
#4-40 #43
#5-40 #39
#6-32 #36
#8-32 #29
#10-24 #25
#12-24 #17
1/4-20 #7
5/16-18 F
3/8-16 5/16
7/16-14 U
1/2-13 27/64
9/16-12 31/64
5/8-11 17/32
3/4-10 21/32
7/8-9 49/64
1″-8 7/8
1-1/8-7 63/64
1-1/4-7 1-7/64
1-1/2-6 1-11/32
1-3/4-5 1-35/64
2″-4-1/2 1-25/32
 
Metric Tap Drill Sizes
Standard UNF Tap Drill Sizes
Standard NPT Tap Drill Sizes