Unified Thread Size Charts
The Unified Thread Standard (UTS) defines a standard thread form and series—along with allowances, tolerances, and designations—for screw threads commonly used in the United States and Canada.
It is the main standard for bolts, nuts, and a wide variety of other used in these countries. It has the same 60° profile as the ISO metric screw thread, but the characteristic dimensions of each UTS thread (outer diameter and pitch) were chosen as an fraction rather than a millimeter value. The UTS is currently controlled by ASME/ANSI in the United States.
UNC - Unified Coarse Thread
| Size | Diameter | TPS | Pitch Diameter | Male Minor Diameter | Female Minor Diameter |
|---|---|---|---|---|---|
| #1 | 0.0730 | 64 | 0.0629 | 0.0544 | 0.0561 |
| #2 | 0.0860 | 56 | 0.0744 | 0.0648 | 0.0667 |
| #3 | 0.0990 | 48 | 0.0855 | 0.0741 | 0.0764 |
| #4 | 0.1120 | 40 | 0.0958 | 0.0822 | 0.0849 |
| #5 | 0.1250 | 40 | 0.1088 | 0.0952 | 0.0979 |
| #6 | 0.1380 | 32 | 0.1177 | 0.1008 | 0.1042 |
| #7 | 0.1640 | 32 | 0.1437 | 0.1268 | 0.1302 |
| #10 | 0.1900 | 24 | 0.1629 | 0.1404 | 0.1449 |
| #12 | 0.2160 | 24 | 0.1889 | 0.1664 | 0.1709 |
| 1/4" | 0.2500 | 20 | 0.2175 | 0.1905 | 0.1959 |
| 5/16" | 0.3125 | 18 | 0.2764 | 0.2464 | 0.2524 |
| 3/8" | 0.3750 | 16 | 0.3344 | 0.3005 | 0.3073 |
| 7/16" | 0.4375 | 14 | 0.3911 | 0.3525 | 0.3602 |
| 1/2" | 0.5000 | 13 | 0.4500 | 0.4084 | 0.4167 |
| 9/16" | 0.5625 | 12 | 0.5084 | 0.4633 | 0.4723 |
| 5/8" | 0.6250 | 11 | 0.5660 | 0.5168 | 0.5266 |
| 3/4" | 0.7500 | 10 | 0.6850 | 0.6309 | 0.6417 |
| 7/8" | 0.8750 | 9 | 0.8028 | 0.7427 | 0.7547 |
| 1" | 1.0000 | 8 | 0.9188 | 0.8512 | 0.8647 |
UNC - Unified Coarse Thread
| Size | Diameter | TPS | Pitch Diameter | Male Minor Diameter | Female Minor Diameter |
|---|---|---|---|---|---|
| #0 | 0.0600 | 80 | 0.0519 | 0.0451 | 0.0465 |
| #1 | 0.0730 | 72 | 0.0640 | 0.0565 | 0.0580 |
| #2 | 0.0860 | 64 | 0.0759 | 0.0674 | 0.0691 |
| #3 | 0.0990 | 56 | 0.0874 | 0.0778 | 0.0797 |
| #4 | 0.1120 | 48 | 0.0985 | 0.0871 | 0.0894 |
| #5 | 0.1250 | 44 | 0.1102 | 0.0979 | 0.1004 |
| #6 | 0.1380 | 40 | 0.1218 | 0.1082 | 0.1109 |
| #8 | 0.1640 | 36 | 0.1460 | 0.1309 | 0.1339 |
| #10 | 0.1900 | 32 | 0.1697 | 0.1528 | 0.1562 |
| #12 | 0.2160 | 28 | 0.1928 | 0.1734 | 0.1773 |
| 1/4" | 0.2500 | 28 | 0.2268 | 0.2074 | 0.2113 |
| 5/16" | 0.3125 | 24 | 0.2854 | 0.2629 | 0.2674 |
| 3/8" | 0.3750 | 24 | 0.3479 | 0.3254 | 0.3299 |
| 7/16" | 0.4375 | 20 | 0.4050 | 0.3780 | 0.3834 |
| 1/2" | 0.5000 | 20 | 0.4675 | 0.4405 | 0.4459 |
| 9/16" | 0.5625 | 18 | 0.5264 | 0.4964 | 0.5024 |
| 5/8" | 0.6250 | 18 | 0.5889 | 0.5589 | 0.5649 |
| 3/4" | 0.7500 | 16 | 0.7094 | 0.6763 | 0.6823 |
| 7/8" | 0.8750 | 14 | 0.8286 | 0.7900 | 0.7977 |
| 1" | 1.0000 | 12 | 0.9459 | 0.9001 | 0.9098 |
Metric Thread Conversion
| Metric Coarse | Metric Fine | UNC | UNF |
|---|---|---|---|
| M2 x 0.4 | - | 1-64 | 1-72 |
| M2.5 x 0.45 | - | 3-48 | 3-56 |
| M3 x 0.5 | - | 4-40 | 4-48 |
| M3.5 x 0.6 | - | 6-32 | 6-40 |
| M4 x 0.7 | - | 8-32 | 8-36 |
| M5 x 0.8 | - | 10-24 | 10-32 |
| M6 x 1 | M6 x 0.75 | 1/4-20 | 1/4-28 |
| M8 x 1.25 | M8 x 1 | 5/16-18 | 5/16-24 |
| M10 x 1.5 | M10 x 1.25 | 3/8-16 | 3/8-24 |
| M12 x 1.75 | M12 x 1.25 | 1/2-13 | 1/2-20 |
| M14 x 2 | M14 x 1.5 | 9/16-12 | 9/16-18 |
| M16 x 2 | M16 x 1.5 | 5/8-11 | 5/8-18 |
| M20 x 2.5 | M20 x 1.5 | 3/4-10 | 3/4-16 |
| M24 x 3 | M24 x 2 | 1-8 | 1-12 |
| M30 x 3.5 | M30 x 2 | 1 1/4-7 | 1 1/8-12 |
| M36 x 4 | M36 x 3 | 1 1/2-6 | 1 1/4-12 |