This thread chart covers UNC, UNF, and 8UN sizes, pairing threads per inch with key dimensions such as thread pitch diameter. Used during design, inspection, or maintenance, a well-organized UNC UNF thread chart serves as a practical reference for selecting and verifying Unified thread sizes.
| Nominal Size | UNC – Coarse Thread | UNF – Fine Thread | 8UN – 8 Thread | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TPI | Pitch Dia (in) | Section ID (sq in) | Tensile Area (sq in) | TPI | Pitch Dia (in) | Section ID (sq in) | Tensile Area (sq in) | TPI | Pitch Dia (in) | Section ID (sq in) | Tensile Area (sq in) | |
| #1 (0.073) | 64 | 0.0629 | 0.00218 | 0.00263 | – | – | – | – | – | – | – | – |
| #2 (0.086) | 56 | 0.0744 | 0.00310 | 0.00370 | 64 | 0.0759 | 0.00339 | 0.00394 | – | – | – | – |
| #3 (0.099) | 48 | 0.0855 | 0.00438 | 0.00487 | 56 | 0.0874 | 0.00451 | 0.00523 | – | – | – | – |
| #4 (0.112) | 40 | 0.0958 | 0.00604 | 0.00661 | 48 | 0.0985 | 0.00566 | 0.00661 | – | – | – | – |
| #5 (0.125) | 40 | 0.1088 | 0.00796 | 0.00830 | 44 | 0.1102 | 0.00730 | 0.00830 | – | – | – | – |
| #6 (0.138) | 32 | 0.1177 | 0.00909 | 0.01015 | 40 | 0.1218 | 0.00909 | 0.01050 | – | – | – | – |
| #8 (0.164) | 32 | 0.1437 | 0.0140 | 0.0147 | 36 | 0.1460 | 0.0147 | 0.0147 | – | – | – | – |
| #10 (0.190) | 24 | 0.1629 | 0.0175 | 0.0200 | 32 | 0.1697 | 0.0200 | 0.0200 | – | – | – | – |
| #12 (0.216) | 24 | 0.1889 | 0.0242 | 0.0258 | 28 | 0.1928 | 0.0258 | 0.0258 | – | – | – | – |
| 1/4 | 20 | 0.2175 | 0.0318 | 0.0364 | 28 | 0.2268 | 0.0364 | 0.0364 | – | – | – | – |
| 5/16 | 18 | 0.2764 | 0.0524 | 0.0625 | 24 | 0.2854 | 0.0580 | 0.0625 | – | – | – | – |
| 3/8 | 16 | 0.3344 | 0.0775 | 0.0878 | 24 | 0.3479 | 0.0878 | 0.0878 | – | – | – | – |
| 7/16 | 14 | 0.3911 | 0.1063 | 0.1187 | 20 | 0.4050 | 0.1187 | 0.1187 | – | – | – | – |
| 1/2 | 13 | 0.4500 | 0.1419 | 0.1599 | 20 | 0.4675 | 0.1599 | 0.1599 | – | – | – | – |
| 9/16 | 12 | 0.5084 | 0.182 | 0.203 | 18 | 0.5264 | 0.203 | 0.203 | – | – | – | – |
| 5/8 | 11 | 0.5660 | 0.226 | 0.256 | 18 | 0.5889 | 0.256 | 0.256 | 8 | 0.5750 | 0.236 | 0.270 |
| 3/4 | 10 | 0.6850 | 0.334 | 0.373 | 16 | 0.7094 | 0.373 | 0.373 | 8 | 0.7000 | 0.351 | 0.398 |
| 7/8 | 9 | 0.8028 | 0.462 | 0.509 | 14 | 0.8286 | 0.509 | 0.509 | 8 | 0.8250 | 0.489 | 0.551 |
| 1 | 8 | 0.9188 | 0.606 | 0.663 | 12 | 0.9459 | 0.663 | 0.663 | 8 | 0.9500 | 0.652 | 0.728 |
| 1 1/8 | 7 | 1.0322 | 0.763 | 0.856 | 12 | 1.0709 | 0.856 | 0.856 | 8 | 1.0750 | 0.840 | 0.929 |
| 1 1/4 | 7 | 1.1572 | 0.969 | 1.073 | 12 | 1.1959 | 1.073 | 1.073 | 8 | 1.2000 | 1.054 | 1.155 |
| 1 3/8 | 6 | 1.2667 | 1.16 | 1.32 | 12 | 1.3209 | 1.32 | 1.32 | 8 | 1.3250 | 1.29 | 1.41 |
| 1 1/2 | 6 | 1.3917 | 1.41 | 1.58 | 12 | 1.4459 | 1.58 | 1.58 | 8 | 1.4500 | 1.55 | 1.68 |
| 1 3/4 | 5 | 1.6201 | 1.90 | 2.20 | – | – | – | – | 8 | 1.7000 | 2.13 | 2.30 |
| 2 | 4.5 | 1.8557 | 2.50 | 2.89 | – | – | – | – | 8 | 1.9500 | 2.77 | 3.02 |
| 2 1/4 | 4.5 | 2.1057 | 3.25 | 3.72 | – | – | – | – | 8 | 2.2000 | 3.58 | 3.86 |
| 2 1/2 | 4 | 2.3376 | 4.00 | 4.62 | – | – | – | – | 8 | 2.4500 | 4.44 | 4.81 |
| 2 3/4 | 4 | 2.5876 | 4.93 | 5.62 | – | – | – | – | 8 | 2.7000 | 5.43 | 5.87 |
| 3 | 4 | 2.8376 | 5.97 | 6.78 | – | – | – | – | 8 | 2.9500 | 6.51 | 7.03 |
| 3 1/4 | 4 | 3.0876 | 7.10 | 8.04 | – | – | – | – | 8 | 3.2000 | 7.70 | 8.30 |
| 3 1/2 | 4 | 3.3376 | 8.30 | 9.40 | – | – | – | – | 8 | 3.4500 | 8.96 | 9.66 |
| 3 3/4 | 4 | 3.5876 | 9.62 | 10.88 | – | – | – | – | 8 | 3.7000 | 10.35 | 11.15 |
| 4 | 4 | 3.8376 | 11.05 | 12.47 | – | – | – | – | 8 | 3.9500 | 11.82 | 12.73 |
Parting Thoughts
MISUMI USA offers a wide range of screws and bolts—both standard and metric—including hex head bolts, narrow head bolts, square head bolts, and more. If you’re unsure which bolt product best suits your application, our engineering team is here to help. For more technical insights, explore our other manufacturing-focused tables and articles, such as a Metric Bolt Torque Chart, and Bolt Grades Chart.
Author: Scott Bredemann | Updated: 12/19/2025
Disclaimer:
The content on this webpage is for informational purposes only. MISUMI makes no guarantees, expressed or implied, regarding the accuracy, completeness, or validity of the information. Performance parameters, tolerances, designs, materials, or processes should not be assumed to reflect third-party suppliers’ or manufacturers’ deliverables within MISUMI’s network. Buyers are responsible for specifying their part requirements