SHMZK 4 PCS Spikes License Plate Screws for Car, Anti Theft Spike Shape Aluminum Car Plate Frame Fastenings Bolt, Cool Licence Plate Screw Set for Car Truck Motorcycle, Car Accessories

My license plate hardware is usually an afterthought—until it isn’t. I installed a set of spike screws to refresh an SUV plate frame and a motorcycle side mount, and the change was immediate. They’re functional fasteners first, but they also add a small, purposeful accent that reads custom without shouting.

What’s in the kit and first impressions

The kit includes four spike-shaped fasteners in silver, with matching washers and lock hardware. Each fastener is an M6 × 1 machine screw, roughly 0.2 inches in thread diameter, and meant to pass through the plate and bracket and lock down with a nut on the back side. The spikes themselves are aluminum alloy, machined cleanly with a bright finish. Mine arrived without burrs or rough edges, and the threads were consistent across the set.

Aluminum is a smart material choice here. It won’t rust, it keeps weight down, and it’s easy to machine into a clean, sharp profile. It isn’t as hard as steel, so you can’t lean on it with impact tools or gorilla torque—but if you install them correctly, there’s no reason they won’t hold up to daily use and weather.

Fit and compatibility: the part to check twice

Before you buy any specialty plate fasteners, check your mount style:

• If your vehicle uses through-holes for the plate bracket (common on motorcycles and many aftermarket frames), the included M6 bolts, washers, lock washers, and nuts make installation straightforward.
• If your bumper or bracket has threaded inserts designed for a specific screw standard (common on many cars), verify it takes M6 × 1. Some North American vehicles expect 1/4-14 or specific OEM screws; M6 will not fit those threads. You can still use the spikes if you can pass a bolt through the bracket and access the back, but if your setup relies on captive threads with no rear access, these won’t be a direct fit.

Plate holes themselves are standard, but the bracket behind them is the variable. The kit is designed around a 0.5-inch mounting hole in the plate area, which is fine. The real constraint is the bracket or bumper thread spec and rear access.

Installation: simple, with a few smart tweaks

My SUV has a plate bracket that allowed a through-bolt, so the included nuts were perfect. On the bike, the side bracket is wide open, so it was even easier.

My steps and recommendations:
1. Protect the paint. A strip of painter’s tape above and below the plate kept the spikes from scuffing the bumper during test fitting.
2. Stack your hardware. On the front (head/spike side), a flat washer under each spike spreads load and protects the plate/frame. On the back, I used the included flat washer, then the lock washer, then the nut.
3. Align and tighten evenly. Hand-thread everything first to avoid cross-threading. Hold the back nut with a 10 mm wrench (typical for M6 nuts) and tighten the spike by hand until snug. You don’t need to torque these aggressively; aluminum can deform if overtightened. Aim for snug plus a quarter turn.
4. Add thread security if needed. On the motorcycle, I used a drop of medium-strength threadlocker on the nut. On the SUV, the lock washer alone was sufficient. Either way, recheck after the first week.
5. Consider washer choice for the look you want. On a black frame, silver washers under shiny spikes look fine; for a fully stealth look, you can omit the front washer or swap to a black nylon washer to protect the frame and reduce visual contrast.

For frames with tight recesses, installing the bolts from the back (washer/lock washer/nut on the front under the spike) can be cleaner, but most plate frames accommodate the standard orientation just fine.

Design and build quality

The spikes are sized well: large enough to be visible and intentional, not so big that they look cartoonish. The taper is even, the surfaces are smooth, and the finish is consistent across all four pieces. Because the spikes are aluminum and the nuts/washers are steel, you’ll have mixed-metal contact. In normal road use, that’s not an issue, but if you live where salt is heavy in winter, a light smear of anti-corrosion compound on the threads is a nice touch.

The aluminum resists oxidation well; after weeks of rain and a couple of touchless washes, mine still look new. The steel washers also held their finish, though it’s always a good habit to rinse winter salt off hardware when you can.

Everyday use and security

As fasteners, they do the simple job—hold the plate flat and tight—without drama. No rattles, no loosening, and no vibration on the bike once I added threadlocker.

As “anti-theft” hardware, think of them as a deterrent rather than a lock. The spike profile makes them harder to grab with bare hands, and using a rear nut adds a step for anyone trying to remove the plate. But these aren’t keyed or proprietary-drive security screws. If theft is a real concern in your area, pair them with a security nut or a hidden lock bracket. For most drivers and riders, the added friction and the look are enough.

Aesthetics

This is where these shine—literally. On the SUV, the silver spikes give a crisp accent against a dark frame, and they align nicely with chrome trim without screaming for attention. On the motorcycle, the spikes lean more into the custom vibe and look right at home. They catch light without being gaudy.

If you’re color-matching a theme, the series includes multiple finishes, and it’s worth choosing hardware that complements your plate frame. Mixing silver spikes with darker washers is fine, but if you’re picky about details, consider swapping front washers for black nylon to keep the focus on the spikes.

Safety and practicality

Spikes are, well, pointy. A few practical notes:
- Keep them oriented and tightened so they don’t protrude unnecessarily. They sit close to the plate by design; there’s no reason for them to extend far out.
- If you park in tight spaces or have kids frequently around the rear bumper, be mindful of placement.
- Some jurisdictions frown on sharp protrusions. These are small and close-set, but it’s still smart to check local regulations.

I haven’t had issues with automatic car washes, but I stick to touchless. If you use brush washes, confirm the spikes won’t snag soft-bristle wraps as they pass over edges.

Durability over time

After installation, I did an early retorque check (always a good idea for new hardware). Everything stayed tight. The lock washers do their job, and with light torque and a drop of threadlocker on the motorcycle setup, there’s been no movement. The aluminum hasn’t marred, and there’s no white oxide bloom or pitting.

Because these are aluminum, I wouldn’t use an impact driver or power tools for install. A hand wrench is all you need. If you ever remove them, back them off cleanly and re-lube the threads to prevent galling.

Value

You get four spikes, washers, lock washers, and nuts in one package, which is exactly what you want for a straightforward upgrade. The machining and finish look better than typical “novelty” fasteners, and the included hardware means you don’t need a trip to the parts bin. For the money, it’s a tidy, low-effort way to add personality and keep plates secure.

The bottom line

Pros:
- Clean machining and corrosion-resistant aluminum
- Included washers, lock washers, and nuts make installs simple
- Visible upgrade without being over the top
- Light deterrent against casual tampering
- Good value for a complete four-piece set

Cons:
- Fit depends on M6 × 1 compatibility or rear access; not a drop-in for every car
- Aluminum threads require sensible torque
- Pointed hardware isn’t ideal for brush car washes or tight, high-contact environments

Recommendation

I recommend these spike screws if you want a subtle aesthetic upgrade and a modest bump in security, and you can confirm M6 × 1 compatibility or have rear access for the included nuts. They install easily, stay put, and look sharp without trying too hard. If you need true anti-theft protection or your vehicle relies on non-M6 captive threads with no rear access, consider a dedicated security fastener kit instead. For most cars, trucks, and motorcycles with standard plate brackets, this is a simple, satisfying hardware upgrade.