NPT (API) American National Pipe Taper Threads Pitch & Tap Drill Size Table

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NPT (API) American National
Pipe Taper
National
dia.		Threads
per
inch		Tap drill sizes
with Reamerwithout Reamer
1/16*
1/8*
1/4*
3/8*
1/2*
3/4*
1*
1.1/4*
1.1/2*
2*		27
27
18
18
14
14
11.1/2
11.1/2
11.1/2
11.1/2		6.10
8.40
10.70
14.25
17.50
22.75
28.50
37.50
43.50
55.00		6.30
8.70
11.10
14.50
18.00
23.25
29.00
38.00
44.00
56.00

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