7/16 inch bolt torque specifications (Grade 2, 5, 8)
A 7/16-14 Grade 5 bolt takes 49 ft-lb (67 N·m) and a Grade 8 takes 70 ft-lb (94 N·m). Both values are for plain, dry steel threads (K 0.20) tightened to 75% of proof load.
Contents11 sections
Key takeaways
- The hex cap screw head is 5/8 in but the standard hex nut is 11/16 in, so you need two wrenches 1.
- Oiled threads need 25% less torque for the same clamp load (K 0.15 vs 0.20) 1: 37 ft-lb for Grade 5.
- 7/16-20 fine thread carries 12.3% more clamp load than 7/16-14 (7,590 against 6,760 lbf in Grade 5).
- Grade 8 at 7/16 in nearly matches Grade 5 at 1/2 in: 70 against 75 ft-lb dry.
Quick facts
| Coarse thread | 7/16-14 UNC |
|---|---|
| Fine thread | 7/16-20 UNF |
| Wrench, hex cap screw | 5/8 in |
| Wrench, hex nut | 11/16 in |
7/16 in bolt specifications
| Thread | Pitch | Tensile stress area |
|---|---|---|
| 7/16-14 (UNC) | 14 threads per inch | 0.1060 in² |
| 7/16-20 (UNF) | 20 threads per inch | 0.1190 in² |
| Wrench, hex cap screw | 5/8 in1 | |
Stress areas from ASME B1.1 as tabulated by Fastenal1.
7/16 in torque by grade
| Grade | Plain, dry K 0.201 | Lubricated K 0.151 | Clamp load |
|---|---|---|---|
| Grade 2 | 32 ft-lb43 N·m | 24 ft-lb32 N·m | 4,370 lbf |
| Grade 5 | 49 ft-lb67 N·m | 37 ft-lb50 N·m | 6,760 lbf |
| Grade 8 | 70 ft-lb94 N·m | 52 ft-lb71 N·m | 9,540 lbf |
Calculated with T = K × D × F, where F is 75% of the bolt’s proof load1 and K is the nut factor for each condition. Real preload from a torque wrench scatters by about ±25%2. When the equipment maker gives a torque, use theirs. How these numbers are made.
7/16 in Grade 2 torque
Proof 55,000 psi · yield 57,000 psi · tensile 74,000 psi1. Clamp load at 75% of proof: 4,370 lbf (7/16-14).
| Condition | K | 7/16-14 | 7/16-20 |
|---|---|---|---|
| Plain steel, dryAs-received black or plain finish, clean threads, no lubricant | 0.201 | 32 ft-lb43 N·m | 36 ft-lb49 N·m |
| Zinc-plated, dryClean zinc-plated threads, no added lubricant | 0.181 | 29 ft-lb39 N·m | 32 ft-lb44 N·m |
| Lubricated (oil or grease)Light oil or grease on the threads and under the nut or head | 0.151 | 24 ft-lb32 N·m | 27 ft-lb36 N·m |
| Copper or metal-free anti-seizeLoctite C5-A copper or N-7000 metal-free anti-seize | 0.163 | 26 ft-lb35 N·m | 29 ft-lb39 N·m |
| Moly pasteMolybdenum disulfide paste | 0.114 | 18 ft-lb24 N·m | 20 ft-lb27 N·m |
7/16 in Grade 5 torque
Proof 85,000 psi · yield 92,000 psi · tensile 120,000 psi1. Clamp load at 75% of proof: 6,760 lbf (7/16-14).
| Condition | K | 7/16-14 | 7/16-20 |
|---|---|---|---|
| Plain steel, dryAs-received black or plain finish, clean threads, no lubricant | 0.201 | 49 ft-lb67 N·m | 55 ft-lb75 N·m |
| Zinc-plated, dryClean zinc-plated threads, no added lubricant | 0.181 | 44 ft-lb60 N·m | 50 ft-lb67 N·m |
| Lubricated (oil or grease)Light oil or grease on the threads and under the nut or head | 0.151 | 37 ft-lb50 N·m | 41 ft-lb56 N·m |
| Copper or metal-free anti-seizeLoctite C5-A copper or N-7000 metal-free anti-seize | 0.163 | 39 ft-lb53 N·m | 44 ft-lb60 N·m |
| Moly pasteMolybdenum disulfide paste | 0.114 | 27 ft-lb37 N·m | 30 ft-lb41 N·m |
7/16 in Grade 8 torque
Proof 120,000 psi · yield 130,000 psi · tensile 150,000 psi1. Clamp load at 75% of proof: 9,540 lbf (7/16-14).
| Condition | K | 7/16-14 | 7/16-20 |
|---|---|---|---|
| Plain steel, dryAs-received black or plain finish, clean threads, no lubricant | 0.201 | 70 ft-lb94 N·m | 78 ft-lb106 N·m |
| Zinc-plated, dryClean zinc-plated threads, no added lubricant | 0.181 | 63 ft-lb85 N·m | 70 ft-lb95 N·m |
| Lubricated (oil or grease)Light oil or grease on the threads and under the nut or head | 0.151 | 52 ft-lb71 N·m | 59 ft-lb79 N·m |
| Copper or metal-free anti-seizeLoctite C5-A copper or N-7000 metal-free anti-seize | 0.163 | 56 ft-lb75 N·m | 62 ft-lb85 N·m |
| Moly pasteMolybdenum disulfide paste | 0.114 | 38 ft-lb52 N·m | 43 ft-lb58 N·m |
Two wrench sizes
7/16 in is one of only two sizes from 1/4 to 1 in where the bolt head and its nut take different wrenches. The ASME B18.2.1 hex cap screw is 5/8 in across flats, while the ASME B18.2.2 hex nut is 11/16 in 1. The other size is 9/16 in. If you hold the nut and turn the head, put the torque wrench on the 5/8 in head; the socket size chart lists the rest.
Coarse or fine thread
The 7/16-14 coarse thread has a tensile stress area of 0.106 in²; the 7/16-20 fine thread has 0.119 in² 1. The fine thread carries 12.3% more clamp load at the same stress, so its calculated torque is higher by the same ratio: 55 ft-lb against 49 ft-lb in Grade 5 dry, 78 against 70 ft-lb in Grade 8. A 7/16-20 bolt torqued from the coarse column ends up about 11% short of the chart clamp load; a 7/16-14 torqued from the fine column is overloaded by 12%.
Which grade you have
Grade 2 has a plain head, Grade 5 three radial lines and Grade 8 six 1. At 7/16 in the proof stresses are 55,000, 85,000 and 120,000 psi 1. That makes the 7/16-14 clamp loads 4,370 lbf for Grade 2, 6,760 lbf for Grade 5 and 9,540 lbf for Grade 8.
7/16 is a size where a grade step and a diameter step are close. A Grade 8 7/16-14 carries 9,540 lbf, slightly more than a Grade 5 1/2-13 at 9,050 lbf, at a slightly lower torque (70 against 75 ft-lb dry) because torque also scales with diameter. Use a Grade 5 nut on a Grade 5 bolt and a Grade 8 nut on a Grade 8 bolt 1. The grades page shows the markings.
When the chart does not apply
The torque values assume the nut factor in each row and size the clamp load to the bolt’s proof load. They do not check the strength of the clamped parts or of a tapped hole, and NASA notes that the default K of 0.20 “should not be used blindly” 2. Fastenal recommends measuring K with a torque-tension test for detailed work 1. When the equipment maker gives a torque, use the maker’s value. For greased, anti-seized or threadlocked threads see dry vs lubricated torque.
Sources
- 1
- 2
- 3
- 4Henkel Corporation (LOCTITE), LOCTITE LB 8012 Moly Paste TDS, April 2015Checked 21 Oct 2026
Spotted a value that doesn’t match its source? Report an error
Related
- 3/8 in3/8-16 Grade 5 bolt torque is 31 ft-lb dry and Grade 8 is 44 ft-lb. Charts for 3/8-16 and 3/8-24 in Grade 2, 5 and 8, dry, zinc-plated and oiled.
- 1/2 in1/2-13 Grade 5 bolt torque is 75 ft-lb dry and Grade 8 is 107 ft-lb. Charts for 1/2-13 and 1/2-20 in Grade 2, 5 and 8, dry, zinc-plated and oiled.
- Grade 5Grade 5 bolt torque from 1/4 in to 1 in, dry, zinc-plated and lubricated, with SAE J429 strength, the three-line head mark and the step down to 74 ksi above 1 in.
- Grade 8Grade 8 bolt torque from 1/4 in to 1 in, dry, zinc-plated and lubricated, with SAE J429 proof, yield and tensile strength and the six-line head marking.
- Grade 2Grade 2 bolt torque from 1/4 in to 1 in, dry, zinc-plated and lubricated, with SAE J429 strength, the drop to 33 ksi proof above 3/4 in, and the plain-head marking.
- Socket size chartSocket sizes for inch hex cap screws, heavy hex structural bolts and metric bolts, including M10, M12, M14 and M22, where ISO and DIN heads differ.
- Bolt torque calculatorBolt torque calculator for SAE and metric bolts by size, thread, grade and lubrication, using T = K × D × F with the proof loads from SAE J429 and ISO 898-1.
- Dry vs lubricated torqueWhy oiled bolts need less torque than dry ones for the same clamp load, with nut factor K values from Fastenal, NASA and Henkel for oil, zinc, anti-seize and moly.