By Kevin West on Saturday, 19 May 2018
Category: Usful Reference

Tap Drill Chart

There are six categories of standard taps. We have broken down the drill size recommendations into those six categories which appear below

 

Metric Size

Letter Size

Metric taps

milimeter Thread

Tap Size

Drill Size

M1.6 x 0.35

1.25mm

M2 x 0.4

1/16

M2.5 x 0.45

2.05mm

M3 x 0.5

#40

M3 x 0.6

2.5mm

M3.5 x 0.6

#33

M4 x 0.7

3.3mm

M4 x 0.75

3.4mm

M5 x 0.8

4.2mm

M5 x 0.9

4.2mm

M6 x 1

5mm

M6.3 x 1

5.5mm

M7 x 1

6.1mm

M8 x 1

7.1mm

M8 x 1.25

6.7mm

M9 x 0.75

8.3mm

M9 x 1

8.1mm

M9 x 1.25

7.9mm

M10 x 1

9.1mm

M10 x 1.25

8.9mm

M10 x 1.5

8.4mm

M11 x 1.50

9.7mm

M12 x 1.25

10.9mm

M12 x 1.5

10.7mm

M12 x 1.75

13/32

M14 x 1.25

12.8mm

M14 x 1.5

12.7mm

M14 x 2

15/32

M16 x 1.5

14.7mm

M16 x 2

35/64

M18 x 1.5

16.8mm

M18 x 2.5

15.8mm

M20 x 2.5

11/16

M22 x 1.5

20.9mm

M24 x 2

22.3mm

M24 x 3

53/64

M30 x 3.5

1-3/64

M36 x 4

1-1/4

NC taps

National Coars

Tap Size

Drill Size

1/4-20NC

#8

5/16-18NC

F

3/8-16NC

5/16

7/16-14NC

U

1/2-13NC

27/64

9/16-12NC

31/64

5/8-11NC

14mm

3/4-10NC

21/32

7/8-9NC

49/64

1-8NC

7/8

1 1/8-7NC

63/64

1 1/4-7NC

1-7/64

1 3/8-6NC

1-3/16

1 1/2-6NC

1-11/32

NS taps

National Standard

 

Tap Size

Drill Size

5/32-32NS

1/8

5/32-36NS

#30

3/16-24NS

#26

3/16-32NS

#22

7/32-24NS

#16

7/32-32NS

#12

1/4-32NS

7/32

1/4-40NS

#1

5/16-32NS

9/32

11/16-16NS

5/8

1-14NS

15/16

NPT taps

National Pipe Thread

 

Tap Size

Drill Size

1/8-27NPT

R

1/4-18NPT

7/16

3/8-18NPT

15mm

1/2-14NPT

23/32

3/4-14NPT

59/64

1 x11-1/2NPT

1-5/32

1-1/4x11-1/2NPT

1-1/2

1-1/2x11-1/2NPT

1-47/64

2x 11-1/2NPT

2-7/32

NF taps

National Fine

Tap Size

Drill Size

1/4-28NF

#3

5/16-24NF

I

3/8-24NF

Q

7/16-20NF

W

1/2-20NF

29/64

9/16-18NF

33/64

5/8-18NF

37/64

3/4-16NF

11/16

7/8-14NF

13/16

1-12NF

29/32

1 1/8-12NF

1-3/64

1 1/4-12NF

1-11/64

1 3/8-12NF

1-19/64

1 1/2-12NF

1-27/64

Number Size Taps

Number size Thread

 

Tap Size

Drill Size

0-80

3/64

1-64

#53

1-72

#53

2-56

#51

2-64

#50

3-48

5/64

3-56

#46

4-36

#44

4-40

#44

4-48

#42

5-40

#39

5-44

#38

6-32

#36

6-40

#33

8-32

#29

8-36

#29

10-24

#25

10-32

#21

12-24

#17

12-28

#15

14-20

#10

14-24

#7

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