7/16 inch bolt torque
A 7/16-14 bolt takes 32 ft-lb in Grade 2, 49 in Grade 5 and 70 in Grade 8, dry, at 75% of proof load; the 7/16-20 fine thread takes 36, 55 and 78. Oiled threads take a quarter less.
Sources checked
| Thread | Grade | DryK 0.20 | Zinc platedK 0.20 | OiledK 0.15 | WaxedK 0.10 | Clamp load |
|---|---|---|---|---|---|---|
| 7/16-14UNC (coarse) | Grade 2 | 32.043.3 | 32.043.3 | 24.032.5 | 16.021.7 | 4,385 lbf19.5 kN |
| Grade 5 | 49.467.0 | 49.467.0 | 37.150.2 | 24.733.5 | 6,777 lbf30.1 kN | |
| Grade 8 | 69.894.6 | 69.894.6 | 52.370.9 | 34.947.3 | 9,567 lbf42.6 kN | |
| 7/16-20UNF (fine) | Grade 2 | 35.748.4 | 35.748.4 | 26.836.3 | 17.924.2 | 4,896 lbf21.8 kN |
| Grade 5 | 55.274.8 | 55.274.8 | 41.456.1 | 27.637.4 | 7,567 lbf33.7 kN | |
| Grade 8 | 77.9106 | 77.9106 | 58.479.2 | 38.952.8 | 10,683 lbf47.5 kN |
Work out 7/16 inch torque
Change grade, threads or preload
7/16-14 Grade 5, dry, plain steel
49.4ft-lb67.0N·m
- Clamp load
- 6,777 lbf (30.1 kN)
- Proof load
- 9,036 lbf
The working
- Tensile stress area. A = 0.7854 × (D − 0.9743 ÷ n)² = 0.7854 × (0.4375 − 0.9743 ÷ 14)² = 0.1063 in²
- Proof load. Grade 5 proof stress is 85,000 psi, so A × stress = 9,036 lbf.
- Clamp load. 75% of proof load = 6,777 lbf.
- Torque. T = K × D × F = 0.2 × 0.4375 in × 6,777 lbf = 593 in-lb ÷ 12 = 49.4 ft-lb (67.0 N·m).
Where the 7/16-14 numbers come from
The 7/16-14 UNC (coarse) thread has a tensile stress area of 0.1063 in². A Grade 8 bolt’s proof stress is 120,000 psi, so its proof load is 12,756 lbf, and 75% of that is a clamp load of 9,567 lbf.
Torque = K × D × F = 0.20 × 0.4375 in × 9,567 lbf = 837 in-lb, or 69.8 ft-lb (94.6 N·m) dry. With oil (K 0.15) it’s 52.3 ft-lb (70.9 N·m).
Other sizes
All sizes on one page: the SAE bolt torque chart.
Questions
What torque for a 7/16-14 Grade 8 bolt?
69.8 ft-lb (94.6 N·m) dry and 52.3 ft-lb (70.9 N·m) oiled, at 75% of proof load. That clamps the joint with 9,567 lbf (42.6 kN).
What torque for a 7/16-14 Grade 5 bolt?
49.4 ft-lb (67.0 N·m) dry, at 75% of proof load; a quarter less with oiled threads.
Coarse or fine thread?
Use whichever the bolt has. The fine 7/16-20 thread has a bigger stress area than the coarse one, so it takes slightly more torque for the same clamp. A thread gauge settles it.
Does this apply to wheel nuts or engine bolts?
No. Use the vehicle maker’s value for those: see lug nut torque by vehicle. These numbers are for general-purpose steel bolts where no spec exists.
Sources
- Portland Bolt: SAE J429: proof load, yield and tensile strength for Grades 2, 5 and 8 (checked October 14, 2026)
- Portland Bolt: Thread pitch chart: UNC and UNF threads per inch and tensile stress areas (checked October 14, 2026)
- Fastenal: Mechanical properties of inch fasteners, with UNC and UNF tensile stress areas (checked October 14, 2026)
- Engineering Toolbox: Threaded bolts: tensile stress area formulas for unified and ISO metric threads (checked October 14, 2026)
- Fastenal: Torque–tension relationship for A307 A, Grade 5, 8 and 9 coarse thread bolts (75% of proof load; K 0.15 and 0.20) (checked October 14, 2026)
- Portland Bolt: Bolt torque chart: T = KDP at 75% of proof load, with K for plain, waxed and galvanized bolts (checked October 14, 2026)
Spotted a number that doesn’t match your manual or a source? Tell us; corrections are logged on the sources page.