License plates are typically attached with standard machine screws: in North America, #6-32 UNC screws about 1/4 inch long are common, while in Europe and many other markets metric M6 x 1.0 screws of similar length are standard. Exact hardware varies by vehicle and plate kit, so it’s best to verify for your car.
Mounting methods differ by region and model. Some plates mount to factory threaded holes in brackets, others rely on self-tapping screws for plastic bumper mounts, and security variants exist to deter theft. This article outlines the most common sizes and practical considerations for attaching license plates.
Regional standards for license plate screws
North America (United States and Canada)
In North America, the standard is a #6-32 UNC machine screw, typically around 1/4 inch (6 mm) long for standard metal mounting surfaces. Heads are usually pan or button type, and plates mount to threaded holes or brackets on the bumper or trunk.
- #6-32 UNC machine screws
- Typical length: 1/4" (6 mm) to 3/8" (9.5 mm) depending on mounting surface
- Common head styles: pan head or button head
Notes: Some vehicles or plate kits use longer screws to clear thicker brackets; anti-theft or tamper-resistant variants are also available.
Europe, Middle East, Africa, and other markets
In Europe and many other markets, the standard is metric: M6 x 1.0 mm screws. Lengths commonly range from 8 to 12 mm for standard plates and up to 16–20 mm if mounting behind trim or through thicker brackets. Head styles vary by manufacturer, with button heads and socket-cap screws common.
- M6 x 1.0 mm machine screws
- Typical lengths: 8–12 mm; longer where necessary
- Common heads: button head or pan head
Security and compatibility considerations: some regions use self-tapping fasteners for plastic bumpers or require a specific torque to avoid over-tightening.
Australia, Asia-Pacific, and other markets
Australia and many Asia-Pacific markets often use M6 x 1.0 mm screws as the regional standard, with lengths commonly 10–16 mm based on mounting surface. As with Europe, the exact hardware depends on the plate kit and vehicle model. Imported vehicles or kits can still use US-style #6-32 screws in certain cases.
- Commonly M6 x 1.0 mm screws
- Lengths typically 10–16 mm
- Head styles: pan or button head; may include washers
Bottom line: verify the exact screw size for your car’s mounting points by checking the owner’s manual, the license plate kit, or the vehicle’s service manual. Auto parts stores stock both US and metric license plate screws and security variants.
Additional considerations for installation
When installing, align holes properly to avoid cross-threading, and avoid overtightening to prevent plate or bumper damage. If your vehicle uses a plastic bumper, opting for shorter, self-tapping screws or hardware recommended by the plate kit can reduce risk. If security is a concern, choose tamper-resistant screws with the compatible driver.
Summary
License plate screws fall into regional standards: #6-32 UNC screws are common in North America, while M6 x 1.0 mm screws are standard in Europe and many other markets. Lengths typically range from about 8 mm to 16 mm depending on mounting surface and plate thickness. Always consult your plate kit or vehicle manual to confirm the correct hardware, and consider security screws if theft is a concern.