Are Motorcycle License Plate Bolts Universal?

One of the most common questions riders ask when upgrading their license plate hardware is whether motorcycle license plate bolts are universal. The short answer is yes — in most cases — and the reason comes down to how motorcycle plates are mounted.

Are motorcycle license plate bolts universal?

Yes, in most cases motorcycle license plate bolts are universal. Because motorcycle license plates are usually mounted using bolts that pass through the plate and are secured with a nut on the back, both M6 and 1/4-20 bolts can be used interchangeably as long as the correct nut and washers are installed.

Why motorcycles are different from cars

Car license plates often screw directly into fixed threaded inserts in the body. This means the exact thread size must match.

Motorcycles are different. Most bikes use a rear plate bracket with open space behind the plate, allowing the bolt to pass through freely and be tightened from the back using a nut. This design makes motorcycle license plate mounting far more flexible.

M6 vs 1/4-20 license plate bolts

• M6 bolts: Common metric size used worldwide
• 1/4-20 bolts: Common imperial size, especially in the USA
• Real-world result: Both work the same way on most motorcycles when a nut is used

What actually matters when choosing license plate bolts

Instead of worrying about thread type, riders should focus on the following:

• Bolt length long enough for the plate and bracket
• Solid metal construction for vibration resistance
• Washers to prevent loosening over time
• A design that does not block letters or numbers

Are there any exceptions?<

You can also read our complete motorcycle license plate bolt buyer’s guide for a full overview of materials, legality, and choosing the right bolts.

Explore our collection of custom motorcycle license plate bolts designed for universal fit, durability, and a premium look.