Bolt Torque Spec Chart
Generic SAE Grade 5 and Grade 8 torque values by bolt size, dry and lubricated.
Read this before using the chart: these are generic reference values for general-purpose fastening, not an engineering torque spec. Anywhere a bolted joint's failure has real consequences — structural, safety-critical, or aerospace/automotive assemblies — use the torque value called out on the actual engineering drawing, OEM service manual, or fastener manufacturer's spec for that specific joint, not a generic chart like this one.
| Size | Grade 5 (dry) | Grade 5 (lubricated) | Grade 8 (dry) | Grade 8 (lubricated) |
|---|---|---|---|---|
| 1/4-20 | 8 ft-lb | 6 ft-lb | 12 ft-lb | 9 ft-lb |
| 5/16-18 | 17 ft-lb | 13 ft-lb | 24 ft-lb | 18 ft-lb |
| 3/8-16 | 31 ft-lb | 23 ft-lb | 44 ft-lb | 33 ft-lb |
| 7/16-14 | 49 ft-lb | 37 ft-lb | 70 ft-lb | 52 ft-lb |
| 1/2-13 | 76 ft-lb | 57 ft-lb | 106 ft-lb | 80 ft-lb |
| 9/16-12 | 109 ft-lb | 82 ft-lb | 153 ft-lb | 115 ft-lb |
| 5/8-11 | 150 ft-lb | 113 ft-lb | 211 ft-lb | 159 ft-lb |
| 3/4-10 | 267 ft-lb | 200 ft-lb | 375 ft-lb | 282 ft-lb |
Need a different unit? Run these through the Torque Conversion Calculator.
Why "dry" and "lubricated" give different numbers for the same bolt
Torque wrench readings measure the force needed to turn the fastener, not the actual clamping force the joint ends up with — most of that torque is fighting friction in the threads and under the head, not stretching the bolt. Lubricant (oil, anti-seize, or plating) cuts that friction significantly, so a lubricated bolt reaches the same actual clamp load at a noticeably lower torque reading than a dry one. Using a dry torque value on a lubricated bolt overloads and can yield or snap it; using a lubricated value on a dry bolt leaves the joint under-clamped.
Grade 5 vs. Grade 8, and why the marking matters
The radial lines on a bolt head (three for Grade 5, six for Grade 8, on SAE fasteners) indicate the material strength, and Grade 8 is meaningfully stronger than Grade 5 at the same size — torquing a Grade 5 bolt to Grade 8 spec risks stretching or shearing it, since it was never rated for that clamp load. Always confirm the actual grade marking on the bolt head before applying any torque value from a chart like this.
Generic charts assume generic conditions
These numbers assume standard SAE-recommended clamp load percentages, standard thread engagement, and typical friction coefficients — a joint with a gasket, a non-standard friction condition, a coated or plated fastener outside "dry/lubricated," or a specific engineering clamp-load requirement can call for a meaningfully different number. This chart is a reasonable default for general shop and hobby fastening; it is not a substitute for a torque spec that was actually engineered for the joint in front of you.