What size are S10 lug nuts?
The size of lug nuts on an S-10 varies by year, wheel type and trim level, so there isn’t a single universal size. This guide outlines the most common sizes and how to verify the correct fit for your truck.
Across the S-10 lineup, most configurations fall into one of two sizing categories: a traditional imperial size (often 9/16-18 UNC) or a metric size (commonly M12x1.5). The exact lug nut you need depends on the wheel studs, seat type, and the wheels you’re using. Always confirm with your vehicle’s documentation or by measuring your setup before purchasing replacements.
Common lug nut sizes you might encounter on an S-10
Below are the sizes you’re most likely to see, depending on year and wheel configuration. Use this as a quick reference, then verify on your specific vehicle.
- 9/16-18 UNC with a conical (tapered) seat — a very common size on many late 1990s to early 2000s GM S-10s with factory steel wheels or many aftermarket wheels.
- M12x1.5 with a conical seat — seen on some later S-10 configurations or with certain aftermarket wheels; requires matching metric lug nuts and often a 19mm or 13/16" wrench size, depending on the exact nut design.
In practice, you may encounter either imperial or metric sizing on a given S-10, especially if the vehicle has been outfitted with aftermarket wheels or refurbished components. Always verify rather than assume, to ensure proper fit and safety.
How to confirm the correct lug nut size for your S-10
The quickest path to the right lug nuts is to confirm against official specs or by directly measuring your current hardware. The steps below help you identify the correct size without guessing.
- Check the owner's manual or the door jamb sticker for wheel and lug nut specifications.
- Inspect the wheel and lug nuts: determine the seat type (acorn/conical vs. other), and note whether the wheel uses imperial or metric sizing.
- Measure the wheel stud diameter: use calipers or a precise ruler. Roughly, around 12mm indicates M12x1.5, while about 14mm (0.55") indicates a 9/16"-18 size; this helps distinguish imperial from metric.
- If in doubt, bring an existing lug nut or the wheel to a parts store or consult the wheel manufacturer for the exact specification before buying replacements.
Correctly matching lug nuts to studs and seats is essential for safety and wheel retention. If you’re upgrading wheels or changing the wheel size, verify compatibility with the lug nuts and the vehicle’s hub and caliper clearances.
Notes on seat types and bolt patterns
Most S-10s use a 5-lug bolt pattern (5x4.75 inches or 5x120.65 mm) and typically employ conical (tapered) lug nut seats. When replacing wheels with aftermarket options, ensure the lug nuts match both the thread size and the seat type of the new wheels. Mismatched seats can cause poor seating, uneven torque, and potential safety risks.
Summary
There isn’t a single universal lug nut size for the S-10. The most common possibilities are 9/16-18 UNC and M12x1.5, with the exact size depending on year, wheel style, and aftermarket modifications. To be certain, check the owner’s manual or door jamb specs, inspect the wheel’s seat type, measure the stud diameter, or consult a parts professional or the wheel manufacturer. With the right size confirmed, you’ll ensure safe, secure wheel mounting for your S-10.
