UNC Unified National Coarse Thread Pitch Drill Size Table

UNC Unified National Coarse Threads & Drill Sizes
Nominal
dia.		 Threads
per
inch		 Tap
drill sizes
mm.
No. 1
No. 2
No. 3
No. 4
No. 5		 64
56
48
40
40		 1.55
1.85
2.10
2.35
2.65
No. 6
No. 8
No. 10
No. 12		 32
32
24
24		 2.85
3.50
3.90
4.50
1/8*
5/32*
3/16*
7/32*		 40
32
24
24		 2.65
3.30
3.80
4.60
1/4*
5/16*
3/8*
7/16*
1/2*		 20
18
16
14
13		 5.10
6.60
8.00
9.40
10.80
9/16*
5/8*
11/16*
3/4*
13/16*
7/8*
1*		 12
11
11
10
10
9
8		 12.20
13.50
15.25
16.50
18.00
19.50
22.25
1.1/8*
1.1/4*
1.3/8*
1.1/2*
1.3/4*
2*		 7
7
6
6
5
4.5		 25.00
28.00
30.75
34.00
39.50
45.00