Which licence plate screws do I need?

Why we don't put screws in the box

It would be easy to toss a bag of screws in with every frame. The trouble is that it would be the wrong bag for a lot of people. There is no single licence plate screw. Here's what varies:

• Metric or imperial. Most Japanese, Korean and European cars use metric screws (usually M6, sometimes M5). Most GM, Ford and Stellantis vehicles use imperial 1/4-inch screws. The two look almost the same and don't swap.
• Machine screw or self-tapping. Some mounts have threaded metal inserts that need a machine screw. Others have plastic grommets that need a sharp, coarse self-tapping screw. Put the wrong type in and you strip the insert or split the grommet.
• Front vs rear. Plenty of cars use one screw at the back and a different one at the front (more on that below).
• Model and year. The same brand changes sizes between models, and sometimes between years of the same model.
• Brackets and adapters. If your front plate is on a tow-hook or bumper bracket, the bracket decides the screw, not the car.

There are simply too many combinations for one kit to fit everyone, and a screw that almost fits is worse than none. So we'd rather be upfront about it: the frame comes on its own, and you use the screws your car needs.

How to read a screw size

Metric: M6 × 1.0 × 20

• M6 is the diameter: 6 mm.
• 1.0 is the thread pitch: 1 mm between threads. M6 is almost always 1.0, and M5 is almost always 0.8, so shops often leave it out.
• 20 is the length in millimetres, measured under the head.

Imperial: 1/4″-14 × 3/4″

• 1/4″ is the diameter, about 6.35 mm. You'll also see it labelled #14 on self-tapping screws.
• 14 is threads per inch. 14 is a coarse self-tapping thread; 1/4″-20 is a finer machine thread (some Fords use it).
• 3/4″ is the length, about 19 mm.

Machine screw or self-tapping?

Pull out one of your current screws and look at the tip.

• Blunt tip, fine even threads: a machine screw. It goes into a threaded metal insert or nut. This is common on rear plates mounted to a trunk lid or tailgate.
• Pointed tip, coarse widely-spaced threads: a self-tapping screw. It cuts its own thread into a plastic grommet or clip nut. This is common on front bumpers.

Buy the same type you took out.

Why your front and back can be different

This catches people out all the time. The rear plate usually bolts to a painted metal trunk lid or tailgate with threaded inserts, so it takes machine screws. The front plate usually goes into the plastic bumper cover through push-in grommets, so it takes self-tapping screws. Same car, two different screws. Some cars are the same front and back, many aren't.

Imports add another twist. Many Japanese-market cars arrive with no front plate holes at all, and the front plate ends up on a bracket whose screws are set by the bracket maker. See front plate on a JDM import in BC.

Check the front and back separately before you buy anything.

Common sizes by make

This is a starting point, not a promise. These are the sizes most commonly reported for each make, but models, years, front vs rear and dealer-installed brackets all change things. Always confirm against a screw from your own car.

If your make isn't listed, or your screw doesn't match, that's normal. Go by the screw, not the table.

How long should they be?

A frame sits between the plate and the car, so the screw has to reach through one more layer. Ours is 5 mm thick. If your current screws only just grab, go about one size longer:

• 16 mm → 20 mm
• 20 mm → 25 mm
• 5/8″ → 3/4″
• 3/4″ → 1″

Don't go much longer than you need. A machine screw that's too long can bottom out in a blind insert before it clamps the plate, and an extra-long self-tapper can hit whatever is behind the bumper cover.

Washers, and not over-tightening

• Use a washer. The mounting holes in our frame are 9.75 mm across, which is generous so they line up on as many cars as possible. A flat washer, or a screw with a built-in washer head, stops a small screw head from sitting inside the hole. A nylon washer under the head is a nice touch and protects the finish.
• Snug, not cranked. The frame is PETG plastic. Tighten until the plate stops moving, then stop. Over-tightening can crack the frame or strip a plastic grommet.
• Go stainless. Road salt eats plain zinc-plated screws, and rust streaks down a plate are hard to get off. Stainless costs about a dollar more.
• Locking screws with a keyed head are worth it if plate theft is a problem where you park.

Where to buy them

• Home Depot, Canadian Tire, RONA and most local hardware stores carry M6 and 1/4″ screws in stainless. Bring an old screw and match it on the thread gauge in the fastener aisle. It takes two minutes and you'll walk out with the right one.
• Online (Amazon.ca and similar), search "stainless licence plate screws" plus your make. Mixed kits with metric and imperial screws, grommets and washers are a good bet if you're not sure.
• Your dealer's parts counter can look up the exact factory part for your model and year.

Not sure what you've got? Email konbiniplates@gmail.com with a photo of one of your screws next to a ruler and we'll help you work it out.