UNC - Unified Coarse Thread
UNC threads ANSI B1.1Nominal Diameter (in) | Threads per inch | Major Diameter (in) | Major Diameter (mm) | Tapping Drill Size (mm) | Pitch (mm) |
---|---|---|---|---|---|
1 | 64 | 0.073 | 1.854 | 1.5 | 0.397 |
2 | 56 | 0.086 | 2.184 | 1.8 | 0.453 |
3 | 48 | 0.099 | 2.515 | 2.1 | 0.529 |
4 | 40 | 0.112 | 2.845 | 2.35 | 0.635 |
5 | 40 | 0.125 | 3.175 | 2.65 | 0.635 |
6 | 32 | 0.138 | 3.505 | 2.85 | 0.794 |
8 | 32 | 0.164 | 4.166 | 3.5 | 0.794 |
10 | 24 | 0.19 | 4.826 | 4 | 1.058 |
12 | 24 | 0.216 | 5.486 | 4.65 | 1.058 |
1/4" | 20 | 0.25 | 6.35 | 5.35 | 1.27 |
5/16" | 18 | 0.313 | 7.938 | 6.8 | 1.411 |
3/8" | 16 | 0.375 | 9.525 | 8.25 | 1.587 |
7/16" | 14 | 0.438 | 11.112 | 9.65 | 1.814 |
1/2" | 13 | 0.5 | 12.7 | 11.15 | 1.954 |
9/16" | 12 | 0.563 | 14.288 | 12.6 | 2.117 |
5/8" | 11 | 0.625 | 15.875 | 14.05 | 2.309 |
3/4" | 10 | 0.75 | 19.05 | 17 | 2.54 |
7/8" | 9 | 0.875 | 22.225 | 20 | 2.822 |
1" | 8 | 1 | 25.4 | 22.85 | 3.175 |
1 1/8" | 7 | 1.125 | 28.575 | 25.65 | 3.628 |
1 1/4" | 7 | 1.25 | 31.75 | 28.85 | 3.628 |
1 3/8" | 6 | 1.375 | 43.925 | 31.55 | 4.233 |
1 1/2" | 6 | 1.5 | 38.1 | 34.7 | 4.233 |
1 3/4" | 5 | 1.75 | 44.45 | 40.4 | 5.08 |
2" | 4.5 | 2 | 50.8 | 46.3 | 5.644 |
2 1/4" | 4.5 | 2.25 | 57.15 | 52.65 | 5.644 |
2 1/2" | 4 | 2.5 | 63.5 | 58.5 | 6.35 |
2 3/4" | 4 | 2.75 | 69.85 | 64.75 | 6.35 |
3" | 4 | 3 | 76.2 | 71.1 | 6.35 |
3 1/4" | 4 | 3.25 | 82.55 | 77.45 | 6.35 |
3 1/2" | 4 | 3.5 | 88.9 | 83.8 | 6.35 |
3 3/4" | 4 | 3.75 | 95.25 | 90.15 | 6.35 |
4" | 4 | 4 | 101.6 | 96.5 | 6.35 |