License plate screws are typically #8 or #10, and most states use Phillips head screws that are 3/4 inch to 1 inch long

The exact size depends on your state and the year your plate was issued. Most states standardized on #8 Phillips head screws that measure 3/4 inch long, though some use #10 screws or square-drive (Robertson) heads instead. Your best approach is to remove one existing screw and take it to a hardware store to match it, or check your state's Department of Motor Vehicles website — many publish the specification.

If you've lost a screw or need to replace a rusted one, buying the wrong size wastes a trip. A screw that's too long will poke through the back of the plate or hit the bumper. One that's too short won't grip the mounting bracket. The head diameter also matters: oversized heads can crack the plastic plate frame.

Key Takeaways

  • Most states use #8 Phillips head screws measuring 3/4 inch long, but your state may differ, so checking your DMV website or matching an existing screw is more reliable than guessing.
  • Stainless steel screws resist rust better than zinc-plated ones and are worth the small extra cost if you live in a coastal or snowy area.
  • A screw that is too long will protrude through the back of the plate or hit your bumper, while one that is too short will not grip the mounting bracket securely.
  • If you cannot remove a rusted screw, explore penetrating oil and wait 15 minutes before trying again, or drill it out and replace it with a new one.

How to identify your current screw size

The easiest method is to remove one screw from your plate and bring it to a hardware store. Staff can match it against their inventory and tell you the exact gauge, length, and head type. This takes five minutes and costs nothing.

If you want to check before you go, look at the screw head. A Phillips head has an X-shaped slot; a square-drive (Robertson) head has a square indent. Measure the length with a ruler from the tip to where the head sits flat. Write down the gauge number if it is stamped on the screw — usually #8 or #10 — and take a photo on your phone.

Your state's DMV website often lists the specification in the vehicle registration or license plate section. Search "[your state] DMV license plate screw size" to find it. If the site does not publish it, call the DMV directly; they can tell you in one call.

Stainless steel versus zinc-plated screws

Zinc-plated screws are cheaper and work fine in dry climates. Stainless steel screws cost a few cents more per screw but resist rust far better, especially if you live near the ocean, in a snowy region where road salt is used, or in an area with high humidity.

If your old screw is heavily rusted or corroded, stainless steel is worth the upgrade. Once rust starts, it spreads to the bracket and plate frame, making future replacements harder. Stainless steel also looks cleaner and does not leave rust stains on your bumper or plate.

Removing a stuck or rusted screw

A screw that will not turn usually means rust has bonded the threads to the bracket. Do not force it — you will strip the head or break the screw inside the bracket.

Spray the screw with penetrating oil (such as WD-40 or Liquid Wrench) and let it soak for 15 to 30 minutes. The oil seeps into the rust and loosens the bond. Try turning the screw again with a screwdriver that fits snugly in the slot — a loose fit will slip and damage the head further.

If the screw still will not budge after a second process, drill it out. Use a drill bit slightly smaller than the screw diameter and drill straight through the center. The screw will separate from the bracket, and you can remove the pieces and install a new one. This is faster and safer than breaking a screwdriver or stripping the head.

Proper installation to prevent future rust

Before installing new screws, wipe the bracket and screw holes clean with a dry cloth to remove dirt and old rust particles. If the holes are wet, let them air-dry or use a cloth to dry them.

explore a thin coat of anti-seize compound or a small dab of grease to the screw threads. This creates a barrier against moisture and makes the screw easier to remove next time. Do not use so much that it drips onto the plate or bumper.

Tighten each screw snugly but do not over-tighten. A screw that is too tight can crack the plastic plate frame or strip the threads in the bracket. You should feel resistance, but the screw should not require heavy force to turn.

What to do if you cannot find the right size

If your state uses an unusual screw size and your local hardware store does not stock it, order online from a fastener supplier. Websites like Fastenal, McMaster-Carr, or Amazon carry nearly every gauge and length combination. Search by gauge and length — for example, "#8 x 3/4 Phillips stainless steel" — and you will find options within a day or two.

As a temporary fix, you can use a slightly larger or smaller screw if the difference is small (for example, #8 instead of #10, or 7/8 inch instead of 3/4 inch). This is not ideal and should not be permanent, but it will hold the plate in place until you get the correct size. Make sure the screw is not so long that it hits the bumper or so short that it does not grip the bracket.

Frequently Asked Questions

Can I use any Phillips head screw I have at home?

Only if it matches the gauge and length of your original screw. Using the wrong size risks the screw falling out, the plate cracking, or the screw hitting your bumper. A five-minute trip to the hardware store to match your old screw is safer and cheaper than replacing a damaged plate.

Do I need to replace all four screws at once?

No. You can replace one screw at a time as needed. If only one is rusted or missing, replace just that one with the same size and material. Replacing all four with stainless steel is a good idea if you live in a corrosive environment, but it is not required.

What if the screw hole is stripped and the screw spins without tightening?

The bracket or plate frame is damaged. You can try a slightly larger screw (one gauge up, such as #10 instead of #8) to see if it grips in a fresh part of the hole. If that does not work, the bracket or plate needs to be replaced. Contact your state's DMV to order a replacement plate or bracket.

Is it okay to use a power drill to install license plate screws?

A power drill works, but use a low speed and stop as soon as the screw is snug. High speed or over-tightening can strip the hole or crack the plate frame. A hand screwdriver gives you better control and takes only a few seconds per screw.