Approximate torque values compiled from various machine tool manufacturers. Proper torque typically runs at 65–70% of the failure torque for the fastener grade. Always verify against the manufacturer's specification. Lubrication reduces required torque by 15–25%.
Important: All values are approximate and not validated for accuracy. Torque varies with material, grade, surface finish, and lubrication. Always defer to the original manufacturer's specification. Lubrication (oil, wax, anti-seize) typically reduces required torque by 15–25%.
Capturing bearing races in housings
Setting preload on certain bearing types
Small fasteners easily over-torqued
Bolts into soft materials (e.g. aluminium manifolds)
Thin-wall housings at risk of distortion
Metric Fasteners
Metric Bolt Torque Values
Steel-to-steel, plain & dry. Grade 10.9 = hex head; Grade 12.9 = SHCS / hex.
| Size | Grade 8.8 | Grade 10.9 | Grade 12.9 |
|---|---|---|---|
| Hex head | Hex head | SHCS / hex | |
| M4 × 0.70 | 1.7 | 2.3 | 3.3 |
| M5 × 0.80 | 3.4 | 4.5 | 6.5 |
| M6 × 1.0 | 7.7 | 11.1 | 13.0 |
| M7 × 1.0 | 13.0 | 18.5 | 21.7 |
| M8 × 1.0 fine | 20 | 29 | 34 |
| M8 × 1.25 coarse | 18.8 | 26.9 | 31.4 |
| M10 × 1.0 fine | 41 | 57 | 67 |
| M10 × 1.25 fine | 38 | 54 | 63 |
| M10 × 1.5 coarse | 37.2 | 53.2 | 62.2 |
| M12 × 1.25 fine | 68 | 97 | 114 |
| M12 × 1.5 fine | 65 | 93 | 109 |
| M12 × 1.75 coarse | 62 | 88 | 103 |
| M14 × 1.5 fine | 108 | 155 | 181 |
| M14 × 2.0 coarse | 103 | 148 | 173 |
| M16 × 2.0 coarse | 161 | 230 | 269 |
| M18 × 2.5 coarse | 222 | 318 | 372 |
| M20 × 2.5 coarse | 314 | 449 | 524 |
| M22 × 2.5 coarse | 428 | 613 | 716 |
| M24 × 3.0 coarse | 543 | 777 | 908 |
| M27 × 3.0 coarse | 796 | 1139 | 1331 |
| M30 × 3.5 coarse | 1079 | 1544 | 1805 |
| M33 × 3.5 coarse | 1468 | 2101 | 2453 |
| M36 × 4.0 coarse | 1886 | 2699 | 3154 |
Values in Nm, plain & dry, steel-to-steel. T=KDF (K=0.20) per Fastenal / ISO 898-1. Approximate only — not validated. Lubricate and reduce by 15–25%.
Lubrication Adjustment Calculator
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Set torque wrench to
Engine oil: × 0.80
Heavy grease / moly: × 0.75
Copper anti-seize: × 0.85
Nickel anti-seize: × 0.78
Dry (no change): × 1.00
Imperial / SAE Fasteners
Standard Bolt Torque Values
Torque in ft·lb (foot-pounds). Dry and oiled (oil/wax/anti-seize) values given separately.
| Diameter in | TPI | Grade 5 | Grade 7 | Grade 8 | Socket Head Cap Screw |
||||
|---|---|---|---|---|---|---|---|---|---|
| Dry | Oiled | Dry | Oiled | Dry | Oiled | Dry | Oiled | ||
| 1/4 | 20 | 8 | 6 | 10 | 8 | 12 | 9 | 14 | 11 |
| 1/4 | 28 | 10 | 7 | 12 | 9 | 14 | 10 | 16 | 13 |
| 5/16 | 18 | 17 | 13 | 21 | 16 | 25 | 18 | 29 | 23 |
| 5/16 | 24 | 19 | 14 | 24 | 18 | 29 | 20 | 33 | 26 |
| 3/8 | 16 | 30 | 23 | 40 | 30 | 45 | 35 | 49 | 39 |
| 3/8 | 24 | 35 | 25 | 45 | 35 | 50 | 40 | 54 | 44 |
| 7/16 | 14 | 50 | 35 | 60 | 45 | 70 | 55 | 76 | 61 |
| 7/16 | 20 | 55 | 40 | 70 | 50 | 80 | 60 | 85 | 68 |
| 1/2 | 13 | 75 | 55 | 95 | 70 | 110 | 80 | 113 | 90 |
| 1/2 | 20 | 90 | 65 | 100 | 80 | 120 | 90 | 126 | 100 |
| 9/16 | 12 | 110 | 80 | 135 | 100 | 150 | 110 | 163 | 130 |
| 9/16 | 18 | 120 | 90 | 150 | 110 | 170 | 130 | 181 | 144 |
| 5/8 | 11 | 150 | 110 | 190 | 140 | 220 | 170 | 230 | 184 |
| 5/8 | 18 | 180 | 130 | 210 | 160 | 240 | 180 | 255 | 204 |
| 3/4 | 10 | 260 | 200 | 320 | 240 | 380 | 280 | 400 | 320 |
| 3/4 | 16 | 300 | 220 | 360 | 280 | 420 | 320 | 440 | 350 |
| 7/8 | 9 | 430 | 320 | 520 | 400 | 600 | 460 | 640 | 510 |
| 7/8 | 14 | 470 | 360 | 580 | 440 | 660 | 500 | 700 | 560 |
| 1 | 8 | 640 | 480 | 800 | 600 | 900 | 680 | 980 | 780 |
| 1 | 12 | 710 | 530 | 860 | 666 | 990 | 740 | 1060 | 845 |
Values in ft·lb. TPI = threads per inch. Compiled from various machine builder specifications and resources. Not validated for accuracy.
Metric Grade Guide
- Grade 8.8 — Common structural bolt. Medium carbon steel, quenched & tempered.
- Grade 10.9 — High-strength. Alloy steel, commonly used in automotive.
- Grade 12.9 — Very high-strength. Socket head cap screws are typically this grade.
SAE Grade Guide
- Grade 5 — Medium-strength. 3 radial lines on head. Most common structural use.
- Grade 7 — Medium-high strength. Medium carbon alloy steel, rolled threads.
- Grade 8 — High-strength. 6 radial lines on head. Used in critical applications.
→ Also try the Power & Torque Calculator → Hydraulic Cylinder Calculator