What size are super duty lug nuts?
Most Ford F-Series Super Duty trucks with eight-lug wheels use 9/16-18 lug nuts with a 60-degree conical seat. However, exact sizing can vary by year, wheel type, and aftermarket components, so confirmation for your specific setup is essential.
Lug nuts secure the wheels to the vehicle’s studs and must match the wheel’s seat type and thread pitch. While 9/16-18 is the common baseline for many Super Duty models, the presence of aftermarket wheels, commercial variants, or special editions means sizes can differ. This article explains the standard sizing and provides practical steps to verify the correct lug nut size for your truck.
Common sizes for Ford Super Duty eight-lug wheels
Before listing the typical factory arrangement, note that the following reflects common practice for eight-lug Super Duty trucks. If you’re using aftermarket or non-standard wheels, sizes may differ.
- 9/16-18 inch thread size with a 60-degree conical seat is by far the most common lug nut specification on eight-lug Ford Super Duty trucks (F-250/F-350, etc.) from many model years.
- Some aftermarket wheels or non-Ford configurations may use alternate thread sizes (for example, 1/2-20) or different seat types; always verify for your exact wheel and year.
In practice, the vast majority of factory-equipped Super Duty trucks with eight lugs use 9/16-18 lug nuts, but the presence of aftermarket wheels or commercial variants can introduce variations that require checking the specific wheel documentation.
How to verify the correct lug nut size
To ensure you have the right lug nuts for your Super Duty, follow these steps and refer to official documentation when possible.
- Check the owner's manual and Ford’s official parts diagrams for your exact year and model to confirm the lug nut size, thread pitch, and seat type.
- Inspect the lug nuts on the wheel: many lug nuts have their size stamped on the head (for example, “9/16-18”). If markings aren’t visible, measure the thread diameter with calipers or a ruler to confirm the correct size.
- Determine the seat type: most factory Ford wheels use a 60-degree conical (tapered) seat, which dictates the appropriate nut style. If you’re unsure, compare the nut’s seating surface to the wheel’s seat or consult the wheel manufacturer.
- Check the wheel manufacturer’s specifications for aftermarket wheels, as they may require a different nut size or seat configuration than the factory setup.
Following these steps helps prevent mismatched nuts that could loosen or damage wheels. When in doubt, contact a Ford dealer or the wheel manufacturer for precise compatibility.
Summary
The standard lug nut size for most Ford Super Duty eight-lug configurations is 9/16-18 with a 60-degree conical seat. However, variations can occur with aftermarket wheels, commercial variants, or year-specific changes. Always verify using the vehicle’s manual, official parts diagrams, or the wheel manufacturer’s specifications, and measure the actual fasteners if necessary. A quick check now can prevent fitment issues and ensure safe, secure wheel installation.
What size are heavy duty truck lug nuts?
The most common semi-truck lug nut size is 33mm for hub-piloted wheels, which are standard on most modern medium and heavy-duty trucks. Another common size, especially for older stud-piloted wheels, is 1-1/2 inches. Some smaller or specialized nuts may use other sizes like 22mm, but it's crucial to verify the exact size before removing a wheel.
Common semi-truck lug nut sizes
- 33mm: The most common size for modern, hub-piloted wheels.
- 1-1/2 inch: Often found on older, stud-piloted wheels.
- 22mm: May be used for some smaller or specialized applications, such as skirt nuts on aluminum wheels.
Important considerations
- Hub-piloted vs. stud-piloted: The wheel type determines the lug nut size. Hub-piloted wheels are more common today and use the 33mm size.
- Metric vs. Imperial: Note that 33mm and 1-1/2 inch are the standard sizes, but they are not exactly the same. Using a 1-5/16 inch socket on a 33mm lug nut can result in a loose fit and potential damage.
- Always verify: It is essential to confirm the correct size with a socket before attempting to remove the lug nut, especially since there can be variations in different models and applications.
What size are the lug nuts on a 2013 Ford F250?
The lug nut size for a 2013 F-250 is M14x1.5 (14mm x 1.5 pitch) with a 13/16" (21mm) or 7/8" hex and a mag/flat seat. It's crucial to confirm the seat style and use the correct socket size and torque specification to ensure proper installation.
Key specifications
- Thread Size: M14x1.5
- Hex Size: 13/16" (21mm) or 7/8"
- Seat Type: Mag/Flat seat
- Torque Spec: 165 ft-lbs (224 Nm)
- Quantity: 32 per truck (OEM)
Important considerations
- Confirm Fitment: Always check your owner's manual or consult a professional to verify the exact specifications for your vehicle and wheel type.
- Correct Socket: Use the correct socket size (either 13/16" or 7/8") to avoid damaging the lug nuts.
- Proper Tightening: Tighten lug nuts in a star pattern and use a torque wrench to achieve the specified torque. Check the tightness again after the first 50-100 miles.
What size socket for 2019 F250 lug nuts?
The correct lug nut socket size for a 2019 F-250 is 21mm or 13/16-inch. These trucks use a 14mm x 1.5 thread pitch.
- Socket size: 21mm or 13/16-inch
- Thread size: 14mm x 1.5
What size are the lug nuts on a 17 F250?
The lug nut size for a 2017 Ford F-250 is M14 x 1.5, which is a metric size for the thread diameter and pitch. The correct hex socket size is 21mm (or 13/16 inch) for most OEM and aftermarket wheels.
- Thread Size: M14 x 1.5 (14mm diameter, 1.5mm pitch)
- Socket/Wrench Size: 21mm or 13/16 inch
- Seat Type: For factory aluminum wheels, the correct seat is typically a flat seat with a washer-like design.
