AI Diesel Technician's Bible™ — complete torque tables, diesel fastener database, sensor thread reference, shop procedures & calculators.
Unlock Full Bible — $9.95SAE Torque Chart
Grade 5 & Grade 8 · Dry and lubricated ft-lb
SAE Bolt Torque Chart — Grade 5 & Grade 8
SAE bolt torque values for Grade 5 and Grade 8 fasteners, dry and lubricated, for bolt sizes 1/4" through 1". Always verify against OEM specifications for critical diesel engine fasteners.
SAE Torque Values — Grade 5 & Grade 8
Values in ft-lb · Lubricated = 75% of dry · Anti-seize = 65% of dry
| Bolt Size | Gr.5 Dry | Gr.5 Oiled | Gr.8 Dry | Gr.8 Oiled |
|---|---|---|---|---|
| 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 | 50 ft-lb | 37 ft-lb | 70 ft-lb | 53 ft-lb |
| 1/2"-13 | 75 ft-lb | 56 ft-lb | 110 ft-lb | 82 ft-lb |
| 9/16"-12 | 110 ft-lb | 82 ft-lb | 155 ft-lb | 116 ft-lb |
| 5/8"-11 | 150 ft-lb | 113 ft-lb | 215 ft-lb | 161 ft-lb |
| 3/4"-10 | 270 ft-lb | 202 ft-lb | 380 ft-lb | 285 ft-lb |
| 7/8"-9 | 395 ft-lb | 296 ft-lb | 600 ft-lb | 450 ft-lb |
| 1"-8 | 590 ft-lb | 442 ft-lb | 900 ft-lb | 675 ft-lb |
Dry torque — clean, unlubricated threads and bearing surfaces.
Lubricated torque — engine oil or light machine oil on threads. Approximately 75% of dry torque.
Anti-seize — reduces torque by approximately 35%. Never use anti-seize on TTY (torque-to-yield) bolts.
OEM always wins — these are general reference values. Always use OEM specifications for head bolts, main caps, rod bolts, and other critical fasteners.
Pro tip: Always verify torque specs against OEM documentation for critical diesel fasteners.
Need engine-specific torque sequences?
The full Bible includes complete torque sequences for Cummins ISX/X15, Detroit DD13/DD15, PACCAR MX-13, and more — with angle torque specs, TTY procedures, and VIN-specific variants.
Unlock the Full Bible — $9.95SAE Torque — FAQ
What is the torque spec for a 1/2"-13 Grade 8 bolt?
A 1/2"-13 Grade 8 bolt torques to 110 ft-lb dry or 82 ft-lb lubricated (engine oil). Always verify against OEM specifications for critical fasteners.
What is the difference between Grade 5 and Grade 8 bolt torque?
Grade 8 bolts are stronger than Grade 5 and require higher torque values — typically 40–50% more torque for the same bolt size. Grade 8 bolts have 6 radial lines on the head; Grade 5 have 3.
How much do I reduce torque for lubricated bolts?
Lubricated torque is approximately 75% of dry torque. Anti-seize reduces torque by approximately 35%. Never use anti-seize on TTY (torque-to-yield) bolts.
Can I use SAE torque charts for diesel engine head bolts?
No. Diesel engine head bolts, rod bolts, and main cap bolts require OEM-specific torque sequences and values. Many are TTY (torque-to-yield) bolts that must be replaced after removal. Always use the OEM service manual for critical engine fasteners.
Related Reference Pages
AI Diesel Technician's Bible™
The complete diesel mechanic reference
Complete torque sequences, diesel fastener database, sensor thread reference, shop procedures, and calculators. One-time purchase — yours forever.
- Full torque tables (SAE + metric + dry/oiled + TTY)
- Diesel fastener database (injectors, turbos, sensors)
- Sensor thread database (NOx, boost, fuel rail, DEF)
- VIN-specific torque variants
- Interactive calculators (tap drill, torque, pressure)
- 12 step-by-step shop procedures
- Printable reference posters
- Shop Mode (high contrast, glove mode)