M14 bolt torque specifications (8.8, 10.9, 12.9)
An M14 x 2 class 8.8 bolt takes 103 ft-lb (140 N·m) dry, and class 10.9 takes 148 ft-lb (200 N·m). Both are for plain steel, dry threads (K 0.20) tightened to a clamp load of 75% of proof load.
Contents13 sections
Key takeaways
- Class 8.8 dry: 103 ft-lb (140 N·m); class 10.9 dry: 148 ft-lb (200 N·m).
- Wrench: 21 mm for ISO 4014/4017 heads, 22 mm for older DIN 931/933 heads 1.
- M14 x 1.5 fine carries about 9% more clamp load than M14 x 2.
- M14 x 1.5 wheel nuts follow the vehicle manual: 150 lb-ft on a 2025 F-150, 130 ft-lb on a 2026 Grand Cherokee.
Quick facts
| Coarse thread | M14 x 2 (115 mm²) |
|---|---|
| Fine thread | M14 x 1.5 (125 mm²) |
| Wrench, ISO 4014/4017 | 21 mm |
| Wrench, DIN 931/933 | 22 mm |
M14 bolt specifications
| Thread | Pitch | Tensile stress area |
|---|---|---|
| M14 x 2 (coarse) | 2 mm pitch | 115.0 mm² |
| M14 x 1.5 (fine) | 1.5 mm pitch | 125.0 mm² |
| Wrench, ISO 4014/4017 | 21 mm1 | |
| Wrench, older DIN 931/933 | 22 mm | |
Stress areas from ISO 898-1 Table 42.
M14 torque by grade
| Grade | Plain, dry K 0.201 | Lubricated K 0.151 | Clamp load |
|---|---|---|---|
| Class 4.6 | 40 ft-lb54 N·m | 30 ft-lb41 N·m | 19.4 kN |
| Class 8.8 | 103 ft-lb140 N·m | 77 ft-lb105 N·m | 50.0 kN |
| Class 10.9 | 148 ft-lb200 N·m | 111 ft-lb150 N·m | 71.6 kN |
| Class 12.9 | 173 ft-lb234 N·m | 130 ft-lb176 N·m | 83.7 kN |
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%3. When the equipment maker gives a torque, use theirs. How these numbers are made.
M14 4.6 torque
Proof 225 MPa · yield 240 MPa · tensile 400 MPa2. Clamp load at 75% of proof: 19.4 kN (M14 x 2).
| Condition | K | M14 x 2 | M14 x 1.5 |
|---|---|---|---|
| Plain steel, dryAs-received black or plain finish, clean threads, no lubricant | 0.201 | 40 ft-lb54 N·m | 44 ft-lb59 N·m |
| Zinc-plated, dryClean zinc-plated threads, no added lubricant | 0.181 | 36 ft-lb49 N·m | 39 ft-lb53 N·m |
| Lubricated (oil or grease)Light oil or grease on the threads and under the nut or head | 0.151 | 30 ft-lb41 N·m | 33 ft-lb44 N·m |
| Copper or metal-free anti-seizeLoctite C5-A copper or N-7000 metal-free anti-seize | 0.164 | 32 ft-lb43 N·m | 35 ft-lb47 N·m |
| Moly pasteMolybdenum disulfide paste | 0.115 | 22 ft-lb30 N·m | 24 ft-lb32 N·m |
M14 8.8 torque
Proof 580 MPa · yield 640 MPa · tensile 800 MPa2. Clamp load at 75% of proof: 50.0 kN (M14 x 2).
| Condition | K | M14 x 2 | M14 x 1.5 |
|---|---|---|---|
| Plain steel, dryAs-received black or plain finish, clean threads, no lubricant | 0.201 | 103 ft-lb140 N·m | 112 ft-lb152 N·m |
| Zinc-plated, dryClean zinc-plated threads, no added lubricant | 0.181 | 93 ft-lb126 N·m | 101 ft-lb137 N·m |
| Lubricated (oil or grease)Light oil or grease on the threads and under the nut or head | 0.151 | 77 ft-lb105 N·m | 84 ft-lb114 N·m |
| Copper or metal-free anti-seizeLoctite C5-A copper or N-7000 metal-free anti-seize | 0.164 | 83 ft-lb112 N·m | 90 ft-lb122 N·m |
| Moly pasteMolybdenum disulfide paste | 0.115 | 57 ft-lb77 N·m | 62 ft-lb84 N·m |
M14 10.9 torque
Proof 830 MPa · yield 940 MPa · tensile 1040 MPa2. Clamp load at 75% of proof: 71.6 kN (M14 x 2).
| Condition | K | M14 x 2 | M14 x 1.5 |
|---|---|---|---|
| Plain steel, dryAs-received black or plain finish, clean threads, no lubricant | 0.201 | 148 ft-lb200 N·m | 161 ft-lb218 N·m |
| Zinc-plated, dryClean zinc-plated threads, no added lubricant | 0.181 | 133 ft-lb180 N·m | 145 ft-lb196 N·m |
| Lubricated (oil or grease)Light oil or grease on the threads and under the nut or head | 0.151 | 111 ft-lb150 N·m | 121 ft-lb163 N·m |
| Copper or metal-free anti-seizeLoctite C5-A copper or N-7000 metal-free anti-seize | 0.164 | 118 ft-lb160 N·m | 129 ft-lb174 N·m |
| Moly pasteMolybdenum disulfide paste | 0.115 | 81 ft-lb110 N·m | 88 ft-lb120 N·m |
M14 12.9 torque
Proof 970 MPa · yield 1100 MPa · tensile 1220 MPa2. Clamp load at 75% of proof: 83.7 kN (M14 x 2).
| Condition | K | M14 x 2 | M14 x 1.5 |
|---|---|---|---|
| Plain steel, dryAs-received black or plain finish, clean threads, no lubricant | 0.201 | 173 ft-lb234 N·m | 188 ft-lb255 N·m |
| Zinc-plated, dryClean zinc-plated threads, no added lubricant | 0.181 | 155 ft-lb211 N·m | 169 ft-lb229 N·m |
| Lubricated (oil or grease)Light oil or grease on the threads and under the nut or head | 0.151 | 130 ft-lb176 N·m | 141 ft-lb191 N·m |
| Copper or metal-free anti-seizeLoctite C5-A copper or N-7000 metal-free anti-seize | 0.164 | 138 ft-lb187 N·m | 150 ft-lb204 N·m |
| Moly pasteMolybdenum disulfide paste | 0.115 | 95 ft-lb129 N·m | 103 ft-lb140 N·m |
Coarse or fine pitch
M14 x 2 coarse has 115 mm² of stress area 2; M14 x 1.5 fine has 125 mm² 1, about 9% more. In class 8.8 dry the fine thread takes 112 ft-lb instead of 103 ft-lb and clamps 54.4 kN instead of 50.0 kN. M14 x 1.5 is also the wheel-stud thread on current Ford and Jeep trucks and SUVs (below); the 2014 F-150 still used the coarser M14 x 2.0, at 148 lb-ft (200 N·m) 6.
Wrench size: ISO or DIN
ISO 4014/4017 M14 heads are 21 mm across the flats; older DIN 931/933 heads are 22 mm 1. Nuts split the same way: DIN 934 M14 nuts are 22 mm, ISO 4032 nuts 21 mm 1. M14 is the last size in this chart with an ISO/DIN difference; M16 is 24 mm in both.
Class 8.8 above and below M16
M14 is still in the lower class 8.8 band: ISO 898-1 sets 580 MPa proof stress for 8.8 up to 16 mm and 600 MPa above 2. The M14 coarse proof load in ISO 898-1 is 66,700 N for 8.8 and 95,500 N for 10.9 2; 75% of those gives the chart’s 50.0 kN (about 11,250 lbf) and 71.6 kN (about 16,090 lbf). Because 10.9 stays at 830 MPa at every size, it runs about 43% above 8.8 here.
ISO 898-1 also notes that for structural bolting the over-16 mm class 8.8 values apply from M12 2, so an M14 structural bolt is not covered by the 580 MPa rows; see structural bolts.
Which class you have
Read the class off the head next to the maker’s mark 2; the bolt grades page shows the markings. Class 12.9 dry is 173 ft-lb (234 N·m).
When the chart does not apply
- Wheel nuts. The 2025 F-150 lists 150 lb-ft (204 N·m) for M14 x 1.5, for threads free of dirt and rust 7. The 2026 Grand Cherokee lists 130 ft-lb (176 N·m) for M14 x 1.50 with a 22 mm socket and says to clean or remove any dirt or oil before tightening 8. Two vehicles on the same thread differ by 20 ft-lb, so use the vehicle’s lug nut torque, not this chart.
- Spark plugs. A 14 mm flat-seat plug in an aluminum head is 18.0 to 21.6 ft-lb per NGK 9, about a fifth of the 8.8 bolt value; see spark plug torque.
Sources
- 1
- 2
- 3
- 4
- 5Henkel Corporation (LOCTITE), LOCTITE LB 8012 Moly Paste TDS, April 2015Checked 21 Oct 2026
- 6
- 7
- 8
- 9NGK Spark Plugs (Niterra), How do I install spark plugs correctly?Checked 21 Oct 2026
Spotted a value that doesn’t match its source? Report an error
Related
- M12M12 x 1.75 bolt torque: 65 ft-lb (88 N·m) for class 8.8 and 93 ft-lb (126 N·m) for 10.9 dry, plus 12.9, M12 x 1.25 fine and the 18 vs 19 mm wrench.
- M16M16 x 2 bolt torque: 161 ft-lb (219 N·m) for class 8.8 and 231 ft-lb (313 N·m) for 10.9 dry, plus 12.9, M16 x 1.5 fine, oiled and moly values.
- Class 8.8Class 8.8 bolt torque from M3 to M30, dry, zinc-plated and lubricated, with the ISO 898-1 proof stress step from 580 MPa to 600 MPa above M16.
- Class 10.9Class 10.9 bolt torque from M3 to M30, dry, zinc-plated and lubricated, with ISO 898-1 strength (830 MPa proof) and how it compares with 8.8 and 12.9.
- 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.
- Ford F-150Ford F-150 lug nut torque by year: 150 ft-lb (204 N·m) on M14 x 1.5 studs since 2015, with the M14 x 2.0 and seven-lug values, quoted from Ford manuals.
- Jeep Grand CherokeeJeep Grand Cherokee lug nut torque by year: 130 ft-lb (176 N·m) on M14 x 1.50 since 2014, 110 ft-lb in the 2011–2012 WK2 and 95 ft-lb for the 2010 WK.