Bolt Size Chart
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| Size | Nominal (Major) | Coarse Thread (UNC) | Fine Thread (UNF) | ||||
| Diameter [in] | Threads Per Inch | Tensile Stress Area [in2] |
Minor Area [in2] | Threads Per Inch | Tensile Stress Area [in2] |
Minor Area [in2] | |
| #0 | 0.06 | --- | --- | --- | 80 | 0.0018 | 0.0015 |
| #2 | 0.086 | 56 | 0.0037 | 0.0031 | 64 | 0.0039 | 0.0034 |
| #4 | 0.112 | 40 | 0.006 | 0.005 | 48 | 0.0066 | 0.0057 |
| #5 | 0.125 | 40 | 0.008 | 0.0067 | 44 | 0.0083 | 0.0072 |
| #6 | 0.138 | 32 | 0.0091 | 0.0075 | 40 | 0.0102 | 0.0087 |
| #8 | 0.164 | 32 | 0.014 | 0.012 | 36 | 0.0147 | 0.0129 |
| #10 | 0.19 | 24 | 0.0175 | 0.0145 | 32 | 0.02 | 0.0175 |
| 1/4" | 0.25 | 20 | 0.0318 | 0.0269 | 28 | 0.0364 | 0.0326 |
| 5/16" | 0.3125 | 18 | 0.0524 | 0.0454 | 24 | 0.058 | 0.0524 |
| 3/8" | 0.375 | 16 | 0.0775 | 0.0678 | 24 | 0.0878 | 0.0809 |
| 7/16" | 0.4375 | 14 | 0.1063 | 0.0933 | 20 | 0.1187 | 0.109 |
| 1/2" | 0.5 | 13 | 0.1419 | 0.1257 | 20 | 0.1599 | 0.1486 |
| 9/16" | 0.5625 | 12 | 0.182 | 0.162 | 18 | 0.203 | 0.189 |
| 5/8" | 0.625 | 11 | 0.226 | 0.202 | 18 | 0.256 | 0.24 |
| 3/4" | 0.75 | 10 | 0.334 | 0.302 | 16 | 0.373 | 0.351 |
| 7/8" | 0.875 | 9 | 0.462 | 0.419 | 14 | 0.509 | 0.48 |
| 1" | 1 | 8 | 0.606 | 0.551 | 12 | 0.663 | 0.625 |
| 1-1/8" | 1.125 | 7 | 0.763 | 0.693 | 12 | 0.856 | 0.812 |
| 1-1/4" | 1.25 | 7 | 0.969 | 0.89 | 12 | 1.073 | 1.024 |
| 1-3/8" | 1.375 | 6 | 1.155 | 1.054 | 12 | 1.315 | 1.26 |
| 1-1/2" | 1.5 | 6 | 1.405 | 1.294 | 12 | 1.581 | 1.521 |
| 1-3/4" | 1.75 | 5 | 1.9 | 1.74 | --- | --- | --- |
| 2" | 2 | 4.5 | 2.5 | 2.3 | --- | --- | --- |
Metric Bolt Thread Size:
Thread sizes for coarse and fine pitch thread were created using the standard sizes from ASME B1.13M. Coarse pitch threads are preferred and should be used whenever possible, as stated in ASME B1.13M.
| Nominal (Major) | Coarse Pitch | Fine Pitch | ||||
| Diameter [mm] | Pitch | Tensile Stress | Minor | Pitch | Tensile Stress | Minor |
| [mm] | Area [mm2] | Area [mm2] | [mm] | Area [mm2] | Area [mm2] | |
| 1.6 | 0.35 | 1.27 | 1.076 | --- | --- | --- |
| 2 | 0.4 | 2.073 | 1.789 | --- | --- | --- |
| 2.5 | 0.45 | 3.391 | 2.98 | --- | --- | --- |
| 3 | 0.5 | 5.031 | 4.473 | --- | --- | --- |
| 3.5 | 0.6 | 6.775 | 6 | --- | --- | --- |
| 4 | 0.7 | 8.779 | 7.75 | --- | --- | --- |
| 5 | 0.8 | 14.18 | 12.68 | --- | --- | --- |
| 6 | 1 | 20.12 | 17.89 | --- | --- | --- |
| 8 | 1.25 | 36.61 | 32.84 | 1 | 39.17 | 36.03 |
| 10 | 1.5 | 57.99 | 52.29 | 1.25 | 61.2 | 56.3 |
| 12 | 1.75 | 84.27 | 76.25 | 1.25 | 92.07 | 86.04 |
| 14 | 2 | 115.4 | 104.7 | 1.5 | 124.5 | 116.1 |
| 16 | 2 | 156.7 | 144.1 | 1.5 | 167.2 | 157.5 |
| 20 | 2.5 | 244.8 | 225.2 | 1.5 | 271.5 | 259 |
| 24 | 3 | 352.5 | 324.3 | 2 | 384.4 | 364.6 |
| 30 | 3.5 | 560.6 | 519 | 2 | 621.2 | 596 |
| 36 | 4 | 816.7 | 759.3 | 2 | 914.5 | 883.8 |
| 42 | 4.5 | 1121 | 1045 | 2 | 1264 | 1228 |
| 48 | 5 | 1473 | 1377 | 2 | 1671 | 1629 |
| 56 | 5.5 | 2030 | 1905 | 2 | 2301 | 2252 |
| 64 | 6 | 2676 | 2520 | 2 | 3031 | 2975 |
| 72 | 6 | 3460 | 3282 | 2 | 3862 | 3799 |
| 80 | 6 | 4344 | 4144 | 1.5 | 4851 | 4798 |
| 90 | 6 | 5591 | 5364 | 2 | 6099 | 6020 |
| 100 | 6 | 6995 | 6740 | 2 | 7562 | 7473 |
| 110 | --- | --- | --- | 2 | 9182 | 9084 |