What size lug nuts are on a F350?
The majority of Ford F-350 Super Duty pickups use 9/16-inch diameter wheel studs with 18 threads per inch (9/16-18). Eight lug nuts accompany a wheel on single-rear-wheel (SRW) configurations, while ten lug nuts are used on dual-rear-wheel (DRW) setups. Variations can occur based on model year, wheel type, and aftermarket components, so it’s important to verify for your exact truck.
To determine the precise lug nut size for your specific F-350, you must account for whether your truck is SRW or DRW, the wheel material (steel vs alloy), and any aftermarket wheels. The standard factory configuration on many F-350s is 9/16-18 with a 60-degree conical seat, but some wheels or generations may differ. Always confirm by checking the wheel label, the lug nut itself (many have size stamps), the owner’s manual, or the wheel manufacturer’s specifications.
Common lug nut sizes and configurations
Below are the configurations you’re most likely to encounter on F-350 models. Use these as a quick reference, but verify on your vehicle before ordering replacements.
- SRW (single rear wheel) with eight lug nuts: typically 9/16-18 with a 60-degree conical seat; wheel compatibility and torque vary by wheel type (steel vs alloy).
- DRW (dual rear wheel) with ten lug nuts: also typically 9/16-18 with a 60-degree conical seat; higher combined load capacity but similar thread pitch and seat shape to SRW in many generations.
- Aftermarket or non-OEM wheels: some wheels may use different thread pitches or seat styles (for example M14x1.5 or 1/2"-20) and require corresponding lug nuts; always verify with the wheel manufacturer and ensure the correct torque specification.
In short, the standard 9/16-18, 60-degree conical-seat lug nuts cover most factory F-350 configurations, with eight lugs on SRW and ten on DRW. Always confirm for your exact build, especially when mixing aftermarket wheels.
How to verify for your specific F-350
Before you buy or install lug nuts, follow these steps to confirm the correct size and seating for your truck and wheels.
- Identify whether your F-350 is SRW or DRW by inspecting the rear axle and wheel arrangement.
- Check the wheel nuts themselves for stamped size information (often on the nut head or near the thread) or refer to the wheel manufacturer's labeling.
- Consult your owner’s manual or the door jamb placard for wheel lug nut size, thread pitch, seat type, and torque specifications appropriate for your model year and wheel type.
- If you’re using aftermarket wheels, verify the lug nut size with the wheel manufacturer and ensure the lug nuts match both the seat shape and thread pitch.
- When in doubt, contact a Ford dealer or qualified tire/wheel shop to confirm the correct lug nut size and torque for your exact F-350 configuration.
Verifying before replacing or purchasing lug nuts helps prevent cross-threading, improper seating, or insufficient torque, which can compromise wheel security and safety.
Summary
Most Ford F-350 trucks use 9/16-18 lugs, with eight lugs per wheel on SRW and ten on DRW models. While this covers the majority of factory configurations, wheel type, year, and aftermarket components can introduce variations. Always verify the exact lug nut size and torque from your vehicle’s manual, wheel labeling, or wheel manufacturer to ensure proper fit and safe operation.
