| Size | Major Dia | Threads Per Inch | Pitch Dia | Minor Dia Externala | Minor Dia Internalb | Minor Dia Area | Tensile Stress Area |
| # | inch | tpi | inch | inch | inch | sq. inch | sq. inch |
| #1* | 0.073 | 64 | 0.0629 | 0.0544 | 0.0561 | 0.00218 | 0.00263 |
| #2 | 0.086 | 56 | 0.0744 | 0.0648 | 0.0667 | 0.0031 | 0.0037 |
| #3* | 0.099 | 48 | 0.0855 | 0.0741 | 0.0764 | 0.00406 | 0.00487 |
| #4 | 0.112 | 40 | 0.0958 | 0.0822 | 0.0849 | 0.00496 | 0.00604 |
| #5 | 0.125 | 40 | 0.1088 | 0.0952 | 0.0979 | 0.00672 | 0.00796 |
| #6 | 0.138 | 32 | 0.1177 | 0.1008 | 0.1042 | 0.00745 | 0.00909 |
| #8 | 0.164 | 32 | 0.1437 | 0.1268 | 0.1302 | 0.01196 | 0.014 |
| #10 | 0.19 | 24 | 0.1629 | 0.1404 | 0.1449 | 0.0145 | 0.0175 |
| #12* | 0.216 | 24 | 0.1889 | 0.1664 | 0.1709 | 0.0206 | 0.0242 |
| ¼ | 0.25 | 20 | 0.2175 | 0.1905 | 0.1959 | 0.0269 | 0.0318 |
| 5/16 | 0.3125 | 18 | 0.2764 | 0.2464 | 0.2524 | 0.0454 | 0.0524 |
| 3/8 | 0.375 | 16 | 0.3344 | 0.3005 | 0.3073 | 0.0678 | 0.0775 |
| 7/16 | 0.4375 | 14 | 0.3911 | 0.3525 | 0.3602 | 0.0933 | 0.1063 |
| ½ | 0.5 | 13 | 0.45 | 0.4084 | 0.4167 | 0.1257 | 0.1419 |
| 9/16 | 0.5625 | 12 | 0.5084 | 0.4633 | 0.4723 | 0.162 | 0.182 |
| 5/8 | 0.625 | 11 | 0.566 | 0.5168 | 0.5266 | 0.202 | 0.226 |
| ¾ | 0.75 | 10 | 0.685 | 0.6309 | 0.6417 | 0.302 | 0.334 |
| 7/8 | 0.875 | 9 | 0.8028 | 0.7427 | 0.7547 | 0.419 | 0.462 |
| 1 | 1 | 8 | 0.9188 | 0.8512 | 0.8647 | 0.551 | 0.606 |
| 1-1/8 | 1.125 | 7 | 1.0322 | 0.9549 | 0.9704 | 0.693 | 0.763 |
| 1¼ | 1.25 | 7 | 1.1572 | 1.0799 | 1.0954 | 0.89 | 0.969 |
| 1-3/8 | 1.375 | 6 | 1.2667 | 1.1766 | 1.1946 | 1.054 | 1.155 |
| 1½ | 1.5 | 6 | 1.3917 | 1.3016 | 1.3196 | 1.294 | 1.405 |
| 1¾ | 1.75 | 5 | 1.6201 | 1.5119 | 1.5335 | 1.74 | 1.9 |
| 2 | 2 | 4.5 | 1.8557 | 1.7353 | 1.7594 | 2.3 | 2.5 |
| 2¼ | 2.25 | 4.5 | 2.1057 | 1.9853 | 2.0094 | 3.02 | 3.25 |
| 2½ | 2.5 | 4 | 2.3376 | 2.2023 | 2.2294 | 3.72 | 4 |
| 2¾ | 2.75 | 4 | 2.5876 | 2.4523 | 2.4794 | 4.62 | 4.93 |
| 3 | 3 | 4 | 2.8376 | 2.7023 | 2.7294 | 5.62 | 5.97 |
| 3¼ | 3.25 | 4 | 3.0876 | 2.9523 | 2.9794 | 6.72 | 7.1 |
| 3½ | 3.5 | 4 | 3.3376 | 3.2023 | 3.2294 | 7.92 | 8.33 |
| 3¾ | 3.75 | 4 | 3.5876 | 3.4523 | 3.4794 | 9.21 | 9.66 |
| 4 | 4 | 4 | 3.8376 | 3.7023 | 3.7294 | 10.61 | 11.08 |
| # | inch | tpi | inch | inch | inch | sq. inch | sq. inch |
| Size | Major Dia | Threads Per Inch | Pitch Dia | Minor Dia Externala | Minor Dia Internalb | Minor Dia Area | Tensile Stress Area |
| * Secondary Size | aForm for UNR thread | bBasic Minor Diameter | |||||
| Design Home | |
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Screw Threads |
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Thread System |
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Unified Screw Threads |
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UNC Coarse |
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UNF Fine |
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UNEF Extra Fine |
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Unified Standard Series |
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Tap Drill |
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Constant Pitch Series |
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Metric Screw Threads |
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Torque in Bolts |
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Introduction |
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Torque Calculator |
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Resources |
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Bibliography |
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