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 |