| Nominal size of nut | Stress area of bolts | Grade 0 nuts | Grade 1 nuts | Grade 3 nuts | Grade 5 nuts | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| For use with bolts of grades A, B, P | For use with bolts of grade S | For use with bolts of grade T | For use of bolts of grades V, X | |||||||
| Min. tensile of grade P bolts 35 tonf/in² | Min. tensile of grade S bolts 50 tonf/in² | Min. tensile of grade T bolts 55 tonf/in² | Min. tensile of grade X bolts 75 tonf/in² | |||||||
| Proof load | ||||||||||
| UNC | UNF | UNC | UNF | UNC | UNF | UNC | UNF | UNC | UNF | |
| in | in² | in² | ton | ton | ton | ton | ton | ton | ton | ton |
| 1/4 | 0.0324 | 0.0368 | 1.134 | 1.288 | 1.620 | 1.840 | 1.782 | 2.024 | 2.430 | 2.760 |
| 5/16 | 0.0532 | 0.0587 | 1.862 | 2.054 | 2.660 | 2.935 | 2.926 | 3.228 | 3.990 | 4.402 |
| 3/8 | 0.0786 | 0.0886 | 2.751 | 3.101 | 3.930 | 4.430 | 4.323 | 4.873 | 5.895 | 6.645 |
| 7/16 | 0.1078 | 0.1198 | 3.773 | 4.193 | 5.390 | 5.990 | 5.929 | 6.589 | 8.085 | 8.985 |
| 1/2 | 0.1438 | 0.1612 | 5.034 | 5.643 | 7.190 | 8.060 | 7.911 | 8.869 | 10.78 | 12.09 |
| 9/16 | 0.184 | 0.205 | 6.440 | 7.176 | 9.200 | 10.25 | 10.12 | 11.28 | 13.80 | 15.37 |
| 5/8 | 0.229 | 0.258 | 8.015 | 9.031 | 11.45 | 12.90 | 12.60 | 14.19 | 17.17 | 19.35 |
| 3/4 | 0.338 | 0.375 | 11.83 | 13.12 | 16.90 | 18.75 | 18.59 | 20.63 | 25.35 | 28.12 |
| 7/8 | 0.467 | 0.513 | 15.97 | 17.96 | 23.35 | 25.65 | 25.68 | 28.21 | 35.02 | 38.47 |
| 1 | 0.612 | 0.667 | 21.42 | 23.34 | 30.60 | 33.35 | 33.67 | 36.68 | 45.90 | 50.02 |
| Stress area x min. tensile strength of bolt = proof load of nuts | ||||||||||