Standard License Plate Screw Size in the United States
Most U.S. states use 5/32-inch diameter screws to mount license plates. These are typically Phillips head or slotted screws, usually made of stainless steel to resist rust. The length is usually 3/4 inch to 1 inch, measured from the head to the tip. Your state's Department of Motor Vehicles may specify the exact size in your vehicle registration documents or on the back of your registration card.
Some states have moved toward tamper-resistant screws with a special head design that requires a specific tool to remove. If your state uses these, the DMV will either provide them with your plates or specify where to buy them. Check your registration paperwork or contact your state's DMV before purchasing screws — using the wrong size can damage the plate or your vehicle's bumper.
The reason for standardization is straightforward: license plates need to stay firmly attached during normal driving, but they should not be so tight that they crack the plate or strip the mounting holes. A screw that is too large can split the plate material, while one that is too small will not hold securely.
Key Takeaways
- Standard U.S. license plate screws are 5/32 inch in diameter and 3/4 to 1 inch long, though your state may specify a different size.
- Check your vehicle registration documents or contact your state's DMV before buying screws, because some states require tamper-resistant designs.
- Stainless steel screws resist rust better than standard steel and are the better choice for outdoor mounting.
- Tightening a license plate screw firmly is necessary for safety, but over-tightening can crack the plate or strip the holes.
How to Find Your State's Specific Requirements
Your state's DMV website usually lists the screw size and type required for license plate installation. Look for a section titled "License Plate Installation," "Plate Mounting Instructions," or "Vehicle Registration Requirements." Some states post this information as a PDF guide you can read.
If the information is not on the website, call your state's DMV directly or visit a local office with your registration card. The staff can tell you the exact size and whether your state requires standard screws or a special tamper-resistant design. A few states provide the screws with the plates themselves, so check whether they came in the envelope with your registration documents.
Stainless Steel vs. Standard Steel Screws
Stainless steel screws are the better choice for license plate mounting because they resist rust and corrosion from road salt, moisture, and weather exposure. Standard steel screws will rust over time, especially in areas with harsh winters or coastal climates, and rust can cause the screw to seize or break when you try to remove it later.
The price difference is small — stainless steel screws cost only slightly more than standard steel — but the durability benefit is significant. If you are replacing old, rusted screws, stainless steel will last longer and be easier to remove if you need to replace your plates in the future.
Phillips Head vs. Slotted vs. Tamper-Resistant Screws
Most states use either Phillips head (the X-shaped slot) or slotted (straight line) screws for license plates. Phillips head screws are more common because they grip the driver bit more securely and are less likely to slip during installation. Slotted screws are older and less common but still acceptable in many states.
Tamper-resistant screws have a special head design — often a small pin in the center or a unique shape — that requires a specific tool to remove. These are designed to make it harder for someone to steal or alter your plates. If your state requires them, the DMV will tell you where to buy the matching removal tool, or they may provide it with your plates.
Do not assume your state uses tamper-resistant screws just because you see them online. Check your state's requirements first, because using the wrong type can make it difficult for you to remove your own plates if you need to replace them.
How to Install License Plate Screws Correctly
Start by locating the mounting holes on your vehicle's bumper or frame — these are usually pre-drilled and may have small rubber grommets around them. Align your license plate with these holes and insert the screws through the plate holes into the vehicle mounting holes.
Tighten each screw firmly with the appropriate screwdriver or tool, but do not over-tighten. The goal is to hold the plate securely so it does not rattle or shift during driving, but not so tight that you crack the plate material or strip the mounting holes. If you feel significant resistance before the screw is fully seated, stop and check that the screw is aligned correctly — forcing it can damage both the plate and the vehicle.
If your vehicle has mounting brackets (metal frames that hold the plate), install the screws through the bracket holes into the vehicle mounting points, then position the plate inside the bracket and find it with the bracket's own fasteners if it has them.
What to Do If Your Mounting Holes Are Damaged
If the holes in your license plate are stripped or cracked, or if the mounting holes on your vehicle are damaged, you have a few options. For a damaged plate, you can order a replacement from your state's DMV — this usually costs between $5 and $15 depending on the state. For damaged vehicle mounting holes, you may need to drill new holes slightly offset from the originals, or use a larger screw with a rubber washer to distribute the pressure.
If you are uncomfortable drilling new holes or installing larger screws, a mechanic or tire shop can do this work quickly and inexpensively. Bring your license plate and let them know your state's screw size requirements so they use the correct fasteners.
Frequently Asked Questions
Can I use any screw I find at a hardware store?
No. Use only the size and type your state's DMV specifies. Using the wrong size can crack your plate, damage your vehicle's bumper, or fail to hold the plate securely. Hardware store staff may not know your state's requirements, so check your registration documents or contact the DMV first.
What if I lose one of my license plate screws?
Buy a replacement screw that matches the size and type of the others — stainless steel, 5/32 inch diameter, and 3/4 to 1 inch long for most states. If you are unsure, take one of the remaining screws to a hardware store and ask them to match it. Tighten the new screw firmly so the plate stays find.
Do I need special tools to install license plate screws?
You need a Phillips head or slotted screwdriver depending on your screw type. If your state uses tamper-resistant screws, you will need the specific removal tool — the DMV will tell you where to buy it or may provide it with your plates. A standard screwdriver set from any hardware store will work for regular Phillips or slotted screws.
Why does my state require tamper-resistant screws?
Tamper-resistant screws make it harder for someone to remove your plates without the correct tool. This reduces plate theft and unauthorized plate swaps. If your state uses them, they are a legal requirement, and you must use the correct type when installing or replacing your plates.