AIYOTAR Metal Electrical Box Cover Plates, 4 PCS Junction Box Covers, 4 Inch Square Flat Blank Electric Box Cover, Solid Cold Rolled Steel Outlet Box Cover for 4x4'' Square/Octagonal Box

Why I keep a pack of these covers on the shelf

I keep a small stash of 4-inch blank covers in the shop because few things clean up an electrical upgrade faster. The AIYOTAR metal box covers do exactly what I need: they sit dead flat, align with standard mounting holes, and give a tidy, inspection-ready finish over junctions I want to remain accessible. After running them through a handful of installs—attic junctions, a garage upgrade, and a laundry-room splice—I’ve got a solid feel for where these covers shine and a couple of places to be mindful.

Build and finish

These covers are stamped from cold-rolled steel and finished in a galvanized, silver-gray coating. The steel is stiff enough that I couldn’t flex or “oil can” the faces with hand pressure, and none of mine arrived bowed. Edges were deburred well—no razor burrs—so I wasn’t nicking gloves or snagging drywall on the way in.

The galvanized surface is uniform and practical. In utility spaces I left them as-is for a clean, industrial look. For a more finished room, I scuffed one cover lightly with a Scotch-Brite pad, hit it with a self-etching primer, and then painted to match wall color. The paint adhered without fisheyes, which tells me the coating isn’t oily out of the box. If you plan to paint, a quick degrease and scuff still pays dividends.

Fit and compatibility

Dimensions are just over 4 inches a side, and they landed flush on every 4-inch square box I tried—both on bare boxes and on boxes with plaster rings. Screw holes lined up precisely with standard 8-32 spacing. I also tested on a 4-inch octagonal box: the covers indexed fine and covered the box edges fully. No interference with conduit fittings, and there’s enough coverage to hide irregular drywall cuts around the box.

Worth noting: these are flat blank plates without a raised center. If you’ve crammed a wirenut bundle that sits proud of the box rim, you may need to re-tuck your splices or use a raised cover. With proper conductor fill, I had no clearance issues.

My set did not include screws. That’s not unusual for blank covers, but plan on having 8-32 machine screws on hand, ideally 1/2-inch length for standard boxes and a tad longer if you’re going through a thick plaster ring.

Installation experience

Installation is straightforward:

• Check that all splices are contained, wirenuts fully seated, and the box fill complies with code.
• If the box front isn’t perfectly co-planar with the wall, shim the device ring or adjust mounting screws to avoid dimpling the cover.
• Align the cover, start both 8-32 screws by hand to avoid cross-threading, and tighten evenly. Don’t over-torque—these covers are rigid, but any flat plate will dimple if you really lean on it.

On a dozen installs, hole alignment was spot-on, no elongated slots or persuasion needed. The plates sat flat against the wall and box every time.

Safety and compliance

These are metal covers, not decorative device plates, and they’re meant to do a simple but essential job: close off a junction box to keep out dust, debris, and fingers. That’s exactly what they do.

A couple of practical points:
- Mine arrived with a UL stamp, which is what I expect on a standard cover. If you’re pulling a permit, inspectors typically want to see listed components throughout the assembly.
- The manufacturer cites a “2732°F high-temperature, flame-retardant” property. In practice, the fire performance that matters is using listed metal components and following code for box fill, conductor ratings, and overcurrent protection. Steel is noncombustible; you don’t need or get a specialized “flame-retardant” performance from a blank cover beyond it being metal. I wouldn’t base a purchase decision on that claim.
- These are not weatherproof. For outdoor or wet-location boxes, you need a cover and box assembly listed for wet locations, often with a gasket and specific fasteners. In damp spaces like basements and garages, the galvanized finish is sufficient and won’t rust with normal exposure.

Where they make sense—and where they don’t

Use them:
- To cap abandoned device openings and maintain access to splices
- In utility areas where a clean, durable metal face is preferred
- Anywhere you need a flat blank on a 4-inch square or octagon box

Avoid them:
- Outdoors or in wet locations where a gasketed, weather-rated cover is required
- On overfilled boxes where a raised cover would be more appropriate
- As a “decorative” substitute for finished plate styles in high-visibility interior design contexts unless you’re painting them to match

Durability over time

Metal covers take abuse better than plastic—no cracking if you bump them with a ladder or toss lumber nearby. I deliberately dinged a spare with a mallet to check resilience; it took a scuff without deforming. In the garage, one plate caught an errant wheelbarrow handle and came away cosmetically scratched but structurally fine. If a cover does get marred, the galvanized surface accepts touch-up paint well.

Long-term, I expect these to outlast whatever wiring changes happen beneath them. If you’re in a corrosive environment (near salt spray, for example), galvanized steel is decent, but stainless would be a step up. For typical residential and light commercial interiors, these are more than adequate.

Finish quality and aesthetics

The silver-gray galvanization is neutral enough to look intentional in utility spaces. For living areas, painting is your friend. My paint test produced an even, durable finish after a scuff and prime, and the crisp, square edges give a tidy outline on drywall. If you’re after a near-invisible patch in a finished room, a mud-in cover system is a different category entirely; for accessible junctions, these strike a good balance between functional and presentable.

Small details that matter

• Flatness: All plates were flat out of the box—no “dish” that can telegraph as a shadow on painted walls.
• Edge treatment: Nicely broken edges; no sharp corners.
• Consistency: Hole spacing and cut quality were consistent across the four-pack.
• Packaging: Mine arrived without scratches or bent corners, which suggests adequate handling during shipping. I didn’t see protective film, but it wasn’t needed.

Value

Buying a four-pack makes sense if you’re mid-project or like to keep spares on hand. Price-wise, these are competitive with what I see locally for similar galvanized blanks, with the convenience of a multi-pack and not having to run to the store mid-wire-run. If you only need one, you may find singles cheaper at a big-box store; for small batches, the cost feels fair given the build quality.

The bottom line

The AIYOTAR covers are exactly what a good blank plate should be: rigid, flat, cleanly finished, and dimensionally reliable. They fit standard 4-inch square and octagon boxes, take paint well, and feel more durable than plastic alternatives. I appreciate the authentic UL marking on my set and the consistently clean edges. I’m less interested in the lofty temperature claims; the meaningful safety story here is simply that they’re metal, well-made, and (in my experience) listed.

Recommendation: I recommend these covers for homeowners and pros who want dependable, no-drama blank plates for 4-inch boxes in dry or damp locations. They install cleanly, hold up to incidental bumps, and can be finished to match surrounding walls. Just be aware they’re not weatherproof for outdoor use, and if your box is overstuffed you may need a raised cover instead. For most interior junctions, these tick the right boxes and earn a place in the kit.