SAE bolt torque specifications. Values shown in ft·lbs for dry/plain steel (K = 0.20), UNC thread.
| Size | Grade 2 | Grade 5 | Grade 8 |
|---|---|---|---|
| #6 | 0.9 | 1.3 | 1.9 |
| #8 | 1.6 | 2.4 | 3.4 |
| #10 | 2.3 | 3.5 | 5.0 |
| 1/4" | 5.5 | 8.4 | 11.9 |
| 5/16" | 11.3 | 17.4 | 24.6 |
| 3/8" | 20.0 | 30.9 | 43.6 |
| 7/16" | 32.0 | 49.4 | 69.8 |
| 1/2" | 48.8 | 75.4 | 106.4 |
| 9/16" | 70.4 | 108.8 | 153.6 |
| 5/8" | 97.1 | 150.1 | 211.9 |
| 3/4" | 172.2 | 266.2 | 375.8 |
| 7/8" | 166.8 | 429.5 | 606.4 |
| 1" | 250.0 | 643.9 | 909.0 |
| 1-1/8" | 354.1 | 794.0 | 1287.6 |
| 1-1/4" | 499.6 | 1120.4 | 1816.9 |
| 1-3/8" | 655.1 | 1469.0 | 2382.2 |
| 1-1/2" | 869.3 | 1949.4 | 3161.3 |
All values in ft·lbs · Dry/plain steel · UNC thread · Click any value for full details
Values are for SAE J429 bolts with unified threads to ASME B1.1, tightened dry to 75% of proof load (K = 0.20). The grade is identified by radial lines on the bolt head: none for Grade 2, three for Grade 5 and six for Grade 8. Proof stress is 55 ksi for Grade 2 up to 3/4" (33 ksi above), 85 ksi for Grade 5 up to 1" (74 ksi above) and 120 ksi for Grade 8 across the range.
The chart shows coarse UNC thread. UNF fine thread has a larger stress area and takes about 10–15% more torque; each size page gives both. If the threads are oiled, waxed or plated, use the matching row on the size page — oiled threads need about 25% less torque than the dry figures here, and using a dry figure on a lubricated bolt can take it past yield.
Numbered sizes (#6, #8, #10) are machine screws below the 1/4" start of SAE J429; their figures apply the same grade proof stress and should be checked against the supplier's rating.