Torque specifications chart
SAE and metric fastener dry torque references (ft·lb and N·m), plus a highlighted heavy-duty wheel-nut section — general reference with sources cited.
| Size | Grade | ft·lb | N·m |
|---|---|---|---|
| 1/4-20 | Grade 5 | 9 | 12 |
| 1/4-20 | Grade 8 | 12 | 16 |
| 5/16-18 | Grade 5 | 17 | 23 |
| 5/16-18 | Grade 8 | 25 | 34 |
| 3/8-16 | Grade 5 | 31 | 42 |
| 3/8-16 | Grade 8 | 44 | 60 |
| 7/16-14 | Grade 5 | 49 | 66 |
| 7/16-14 | Grade 8 | 70 | 95 |
| 1/2-13 | Grade 5 | 75 | 102 |
| 1/2-13 | Grade 8 | 106 | 144 |
| 9/16-12 | Grade 5 | 109 | 148 |
| 9/16-12 | Grade 8 | 154 | 209 |
| 5/8-11 | Grade 5 | 150 | 203 |
| 5/8-11 | Grade 8 | 212 | 287 |
| 3/4-10 | Grade 5 | 267 | 362 |
| 3/4-10 | Grade 8 | 376 | 510 |
| 7/8-9 | Grade 5 | 429 | 582 |
| 7/8-9 | Grade 8 | 606 | 822 |
| 1-8 | Grade 5 | 644 | 873 |
| 1-8 | Grade 8 | 909 | 1232 |
| M6 × 1.0 | 10.9 | 10.3 | 14 |
| M6 × 1.0 | 8.8 | 7.4 | 10 |
| M8 × 1.25 | 10.9 | 25.8 | 35 |
| M8 × 1.25 | 8.8 | 18.4 | 25 |
| M10 × 1.5 | 10.9 | 50.9 | 69 |
| M10 × 1.5 | 8.8 | 36.1 | 49 |
| M12 × 1.75 | 10.9 | 88.5 | 120 |
| M12 × 1.75 | 8.8 | 62.7 | 85 |
| M14 × 2.0 | 10.9 | 140.1 | 190 |
| M14 × 2.0 | 8.8 | 99.6 | 135 |
| M16 × 2.0 | 10.9 | 217.6 | 295 |
| M16 × 2.0 | 8.8 | 154.9 | 210 |
| M18 × 2.5 | 10.9 | 298.7 | 405 |
| M18 × 2.5 | 8.8 | 213.9 | 290 |
| M20 × 2.5 | 10.9 | 427.8 | 580 |
| M20 × 2.5 | 8.8 | 302.4 | 410 |
Source: Fastenal Torque-Tension Relationship (SAE J429 Grade 5 & 8), dry K≈0.20 · ISO 898-1 property classes 8.8 / 10.9 — dry torque via T=K·d·F (K≈0.20, ~75% proof), same industrial methodology
Dry/plain fastener estimates only. Lubricated fasteners need lower torque. Always prefer the assembly OEM specification.
Heavy-duty wheel nuts — separate caution
Wheel-nut torque is safety-critical. The ranges below are typical industry references for common Class 8 hub-piloted studs — not a universal guarantee. Always verify the vehicle / wheel manufacturer’s installation procedure (clean dry threads vs lube, star pattern, re-torque after first miles).
| Stud / style | Typical range |
|---|---|
| M22 × 1.5 (hub-piloted Class 8) | 450–500 ft·lb (610–678 N·m) |
| 3/4-16 / 1-1/8-16 (older stud-piloted — verify style) | 450–500 ft·lb (610–678 N·m) |
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