UNC/UNF Tables
Unified UNF Screw Threads ANSI B1.1
Diameter |
Threads Per Inch (TPI) |
Major diameter (In)
|
Major diameter (mm)
|
Pitch Diameter (mm) |
Tap Drill Size(mm)
|
N° 0 |
80 |
0.060 |
1.524 |
0.317 |
1.25 |
N° 1 |
72 |
0.073 |
1.854 |
0.353 |
1.55 |
N° 2 |
64 |
0.086 |
2.184 |
0.397 |
1.90 |
N° 3 |
56 |
0.099 |
2.515 |
0.453 |
2.15 |
N° 4 |
48 |
0.112 |
2.845 |
0.529 |
2.40 |
N° 5 |
44 |
0.125 |
3.175 |
0.577 |
2.70 |
N° 6 |
40 |
0.138 |
3.505 |
0.635 |
2.95 |
N° 8 |
36 |
0.164 |
4.166 |
0.705 |
3.50 |
N° 10 |
32 |
0.190 |
4.826 |
0.794 |
4.10 |
N° 12 |
28 |
0.216 |
5.486 |
0.907 |
4.70 |
1/4” |
28 |
0.250 |
6.350 |
0.907 |
5.50 |
5/16” |
24 |
0.313 |
7.938 |
1.058 |
6.90 |
3/8” |
24 |
0.375 |
9.525 |
1.058 |
8.50 |
7/16” |
20 |
0.438 |
11.112 |
1.270 |
9.90 |
1/2” |
20 |
0.500 |
12.700 |
1.270 |
11.50 |
9/16” |
18 |
0.563 |
14.288 |
1.411 |
12.90 |
5/8” |
18 |
0.625 |
15.875 |
1.411 |
14.50 |
3/4” |
16 |
0.750 |
19.050 |
1.587 |
17.50 |
7/8” |
14 |
0.875 |
22.225 |
1.814 |
20.40 |
1” |
12 |
1.000 |
25.400 |
2.117 |
23.25 |
1 1/8” |
12 |
1.125 |
28.575 |
2.117 |
26.50 |
1 1/4” |
12 |
1.250 |
31.750 |
2.117 |
29.50 |
1 3/8” |
12 |
1.375 |
34.925 |
2.117 |
32.75 |
1 1/2” |
12 |
1.500 |
38.100 |
2.117 |
36.00 |
UNC threads according ANSI B1.1
Diameter |
Threads Per Inch (TPI) |
Major diameter (In)
|
Major diameter (mm)
|
Pitch Diameter (mm) |
Tap Drill Size(mm)
|
N° 1 |
64 |
0.073 |
1.854 |
0.397 |
1.50 |
N° 2 |
56 |
0.086 |
2.184 |
0.453 |
1.80 |
N° 3 |
48 |
0.099 |
2.515 |
0.529 |
2.10 |
N° 4 |
40 |
0.112 |
2.845 |
0.635 |
2.35 |
N° 5 |
40 |
0.125 |
3.175 |
0.635 |
2.65 |
N° 6 |
32 |
0.138 |
3.505 |
0.794 |
2.85 |
N° 8 |
32 |
0.164 |
4.166 |
0.794 |
3.50 |
N° 10 |
24 |
0.190 |
4.826 |
1.058 |
4.00 |
N° 12 |
24 |
0.216 |
5.486 |
1.058 |
4.65 |
1/4” |
20 |
0.250 |
6.350 |
1.270 |
5.35 |
5/16” |
18 |
0.313 |
7.938 |
1.411 |
6.80 |
3/8” |
16 |
0.375 |
9.525 |
1.587 |
8.25 |
7/16” |
14 |
0.438 |
11.112 |
1.814 |
9.65 |
1/2” |
13 |
0.500 |
12.700 |
1.954 |
11.15 |
9/16” |
12 |
0.563 |
14.288 |
2.117 |
12.60 |
5/8” |
11 |
0.625 |
15.875 |
2.309 |
14.05 |
3/4” |
10 |
0.750 |
19.050 |
2.540 |
17.00 |
7/8” |
9 |
0.875 |
22.225 |
2.822 |
20.00 |
1” |
8 |
1.000 |
25.400 |
3.175 |
22.85 |
1 1/8” |
7 |
1.125 |
28.575 |
3.628 |
25.65 |
1 1/4” |
7 |
1.250 |
31.750 |
3.628 |
28.85 |
1 3/8” |
6 |
1.375 |
34.925 |
4.233 |
31.55 |
1 1/2” |
6 |
1.500 |
38.100 |
4.233 |
34.70 |
1 3/4” |
5 |
1.750 |
44.450 |
5.080 |
40.40 |
2” |
4 1/2" |
2.000 |
50.800 |
5.644 |
46.30 |
2 1/4" |
4 1/2" |
2.250 |
57.150 |
5.644 |
52.65 |
2 1/2" |
4 |
2.500 |
63.500 |
6.350 |
58.50 |
2 3/4" |
4 |
2.750 |
69.850 |
6.350 |
64.75 |
3” |
4 |
3.000 |
76.200 |
6.350 |
71.10 |
3 1/4" |
4 |
3.250 |
82.550 |
6.350 |
77.45 |
3 1/2" |
4 |
3.500 |
88.900 |
6.350 |
83.80 |
3 3/4" |
4 |
3.750 |
95.250 |
6.350 |
90.15 |
4" |
4 |
4.000 |
101.600 |
6.350 |
96.50 |