License plate screws are typically 1/4-inch diameter with a Phillips head, and most states supply them with your plate

The standard screw for mounting a license plate in the United States is a 1/4-inch diameter Phillips head screw, usually between 3/4 inch and 1 inch long. When you receive a new plate from your state's motor vehicle department, the screws almost always come in the same envelope or bag. If you have lost them or need replacements, a hardware store can sell you stainless steel 1/4-inch Phillips screws in the same length.

The reason 1/4-inch is standard is practical: it fits the pre-drilled holes in every license plate frame sold in the United States, and it is small enough not to crack the plastic frame or metal plate, but large enough to hold securely even on rough roads. Stainless steel matters because it resists rust and corrosion from road salt and moisture—a cheap steel screw will seize or corrode within a year or two in most climates.

Key Takeaways

  • Standard license plate screws are 1/4-inch diameter Phillips head, 3/4 to 1 inch long, and usually come with your new plate from the state.
  • Stainless steel screws last much longer than plain steel and resist rust from road salt and weather.
  • If you need replacements, a hardware store can sell you the exact size for a few dollars.
  • Do not use screws larger than 1/4-inch diameter, as they can crack the plate or frame and may not fit the pre-drilled holes.
  • Tighten screws firmly but do not over-tighten, which can strip the holes or crack plastic frames.

Where to find replacement screws

If your original screws are lost or damaged, you have two straightforward options. First, contact your state's motor vehicle department—many will send replacement screws for free or a small fee, since they are inexpensive and the department has them on hand. Second, visit any hardware store and ask for 1/4-inch Phillips head stainless steel screws in 3/4-inch or 1-inch length. The staff can show you what is in stock, and a pack of four or eight screws costs between two and five dollars.

Online retailers like Amazon also stock these screws, but ordering them for a few dollars plus shipping makes sense only if you are ordering other items at the same time. A local hardware store is faster and you can see the screws before you buy.

Why the size matters

License plate holes are drilled to accept 1/4-inch screws specifically. If you use a smaller diameter screw, it will not grip the frame or plate and will fall out. If you use a larger screw—say, 5/16-inch or 3/8-inch—it will not fit the hole at all, or it will crack the plastic frame or the aluminum plate as you tighten it. The pre-drilled holes are not adjustable, so matching the original size is essential.

The length also matters, but less critically. A 3/4-inch screw is the most common, but 1-inch screws work fine too—they straightforward protrude a bit further through the frame. Never use a screw longer than 1 1/4 inches, as it can poke through the back of the frame and catch on wires or hoses behind the bumper.

How to install or replace license plate screws

Start by positioning your license plate frame against the bumper or mounting surface where it will sit. Align the frame so the plate is level and centered. Insert the first screw through the top-left hole of the frame and into the pre-drilled hole in the bumper or bracket. Hand-tighten it first so you can still adjust the frame if needed.

Once the frame is positioned correctly, tighten all four screws in a cross pattern—top-left, bottom-right, top-right, bottom-left. This distributes pressure evenly and prevents the frame from warping. Use a Phillips head screwdriver and tighten firmly, but stop before you feel strong resistance. Over-tightening can strip the holes in plastic frames or crack the plate itself. If you are mounting to plastic, be especially gentle.

After installation, check the screws after your first few drives. Vibration can loosen them slightly, so a quick tightening after a week of driving is normal maintenance.

Stainless steel vs. other materials

Stainless steel is the only practical choice for license plate screws. Plain steel screws will rust within months in wet climates or areas that use road salt, and rust makes them nearly impossible to remove later. Zinc-plated screws offer some protection but corrode faster than stainless. Brass or aluminum screws are too soft and will strip or bend under the vibration of driving.

The small extra cost of stainless steel—usually just a dollar or two more for a pack—is worth it because you will not face a seized screw if you ever need to remove or replace the plate. Stainless screws can sit for years and still come out easily with a screwdriver.

What to do if a screw is stuck or stripped

If a screw is rusted or corroded and will not turn, spray it with penetrating oil (like WD-40) and let it sit for 15 to 30 minutes. Then try again with a screwdriver that fits the Phillips head snugly. If the head is stripped and the screwdriver spins without turning the screw, try wrapping a rubber band around the screw head to increase grip, or use a slightly larger Phillips screwdriver if you have one.

If the screw still will not budge, you may need to drill it out. Use a drill bit slightly smaller than the screw diameter and carefully drill through the center of the screw. Once the head separates, you can remove the frame and back out the remaining shaft with pliers. This is a last resort and is worth doing only if the screw is truly stuck. If you are not comfortable drilling, a local mechanic or tire shop can do it quickly for a small fee.

Frequently Asked Questions

Can I use a different size screw if I can't find 1/4-inch?

No. The holes in your license plate frame are drilled specifically for 1/4-inch screws. A smaller screw will not grip, and a larger one will not fit or will crack the frame. A hardware store can order 1/4-inch screws if they are not in stock, or you can contact your state's motor vehicle department for replacements.

Do I need to use the exact same length screw?

Not exactly. A 3/4-inch screw is most common, but 1-inch screws work fine too. Do not go longer than 1 1/4 inches, as the screw may poke through the back of the frame and catch on bumper components. If you are unsure, bring your old screw to the hardware store and match the length.

What if my license plate frame has different-sized holes?

Some aftermarket frames are designed for different screw sizes. Check the documentation that came with the frame, or measure one of the existing holes with a ruler or caliper. If you cannot determine the size, take the frame to a hardware store and staff can measure it for you.

Can I use a screw gun or power drill to tighten license plate screws?

You can, but use the lowest speed setting and stop as soon as you feel resistance. Power tools make it straightforward to over-tighten and strip the holes or crack a plastic frame. A hand screwdriver gives you better control and feel for when the screw is tight enough.

Do I need washers under the screw heads?

No. Standard license plate screws are designed to work without washers. Washers can actually cause problems by lifting the screw head away from the frame and creating a gap where dirt and moisture collect. Stick with the screw alone.