Tap Chart - Helicoil Threads

Tap size Drill size

2-56

3/32

3-48

#33

4-40

#31

4-48

#30

5-40

#30

6-32

#25

6-40

#26

8-32

#17

10-24

13/64

10-32

#7

12-24

#2

1/4-20

17/64

1/4-28

G

5/16-18

Q

5/16-24

21/64

3/8-16

X

3/8-24

25/64

7/16-14

29/64

7/16-20

29/64

1/2-13

33/64

1/2-20

33/64