Most license plates in the United States are mounted with #6-32 or 1/4-14 machine screws, while European plates typically use metric M6 x 1 screws. Lengths usually range from about 12 mm to 25 mm, depending on plate thickness and bumper geometry. Always verify the exact size for your vehicle and plate kit.
This article explains how to identify the correct screw size for your license plate, with region-specific guidance and practical installation tips to ensure a secure, compliant mount.
Regional standards
United States and Canada
Most U.S. plates are attached to holes in the bumper, trim, or plate frame using machine screws. The two sizes you’re most likely to encounter are #6-32 and 1/4"-14. The exact choice depends on your car’s mounting hardware and whether your plate holes are threaded or require self-tapping screws.
- #6-32 machine screws — common for standard license plates; typical length 1/2" to 1" (12–25 mm).
- 1/4"-14 machine screws — used on some vehicles or frames; typical length 3/4" to 1" (19–25 mm).
- Self-tapping screws (often used for non-threaded mounting points) sized to fit the hole, commonly in the #6 or #8 range.
Conclusion: Check your vehicle’s manual or the hardware that came with your plate or frame. If your holes are threaded, use machine screws; if they’re non-threaded, self-tapping screws are typically required.
Europe and other regions
European vehicles typically use metric screws for license plates. The standard size is M6 with a 1.0 mm thread pitch, and typical screw lengths range from about 12 mm to 20 mm, depending on plate thickness and bumper geometry. Some manufacturers and plate frames may use longer screws.
- M6 x 1 mm screws — standard, widely used across Europe; length 12–20 mm is common.
- Alternatives (less common) include shorter M6 screws or, in some cases, self-tapping variants for plastic bumpers.
Conclusion: For European plates or international kits, choose M6 x 1 mm screws of appropriate length, and consider stainless steel for corrosion resistance. Always verify with the plate kit or local regulations.
How to determine the right size for your vehicle
To accurately identify the correct screws for your license plate, follow these steps:
- Inspect whether the mounting holes are threaded or require self-tapping screws.
- Measure the diameter of the hole or the existing screw using calipers or a ruler, and compare to common sizes (#6-32, 1/4"-14, M6 x 1).
- Check your vehicle’s owner manual or the screws that came with your plate or frame for recommended hardware.
- Choose corrosion-resistant material (stainless steel or zinc-coated) and consider tamper-resistant options if security is a concern.
- Ensure the screw length is sufficient to bite through any plate/frame material but not protrude beyond the bumper or hardware.
Conclusion: The exact size varies by region and vehicle; using the correct size ensures a secure, compliant mount and avoids damage to the plate or bumper.
Summary
License plate screw sizes are region-dependent: #6-32 and 1/4"-14 are common in the United States, while Europe typically uses M6 x 1 screws. Verify hole threading, plate thickness, and regional regulations, and choose corrosion-resistant hardware. When in doubt, consult your vehicle’s manual or the plate/frame supplier for the exact specifications.