Qlvily 3 Packs 4 Inch Metal Electrical Box Cover Plates, Junction Box Cover, Electrical Box Cover, Corrosive Resistant Cover for Electrical Junction Box, Galvanized, Sliver

I keep a small bin of 4-inch square box covers in my shop because they disappear at the worst possible time—usually right before an inspection. After running the Qlvily 4-inch galvanized covers through a few garage, basement, and shed jobs, they’ve earned a spot in that bin. They’re straightforward blanks that do what they’re supposed to do: cover a 4-inch square junction box cleanly, securely, and without fuss.

Build quality and materials

These are stamped from galvanized steel at 1.65 mm thick, which is noticeably stouter than bargain-bin blanks. You feel it right away—there’s very little flex when you try to twist or bow the plate by hand. That extra thickness helps the cover sit flat and resist dings if you’re working around it with lumber, ladders, or conduit. It also gives the screw areas enough meat that they don’t “cone” inward when you cinch them down.

The galvanization is a practical, matte silver rather than a showy bright finish. I prefer that in utility spaces; it blends with standard steel boxes without calling attention to itself. The edges on my set were decently deburred. Are they as silky as premium architectural plates? No. But I didn’t find any razor edges, and a quick glove-free handle didn’t raise red flags. As with any stamped steel cover, I still recommend gloves if you’re reaching into tight framing around sharp metal.

I checked a plate that lived for several weeks in a damp basement near a dehumidifier and another in an uninsulated garage through a couple of heavy summer storms. No flash rust, no white oxidation blooms—just the same dull silver I installed. Galvanization won’t turn a blank into a weatherproof enclosure, but it does hold up to incidental moisture, which is exactly what you want for utility environments.

Fit and compatibility

These are true 4-by-4-inch blanks sized for standard 4-inch square metal junction boxes with corner screw tabs. If you’re working with the larger 4-11/16-inch boxes, these won’t span the opening. That sounds obvious, but it’s a common misorder when you’re buying online and juggling multiple box sizes on a project. Measure your boxes or check the carton before you commit.

On the boxes I tested—Raco and Steel City 4-inch squares with and without extension rings—the hole spacing lined up perfectly, and the plate sat flush across both the box and the raised ring. The corners are square and crisp, so there isn’t any weird interference with plaster ears or ring lips.

The mounting holes use a keyhole-style geometry that lets you hang the plate on partially backed-out screws, then slide and tighten. If you’re accessing the splice later, you can loosen and swing off the cover without removing both screws entirely. It’s a small convenience, but it speeds up repetitive work during rough-in and trim.

A note on hardware: my pack didn’t include screws. Most metal boxes ship with 8-32 machine screws, and I typically reuse those or pull from a bulk pack. If you’re covering older boxes where the screws went missing, have 8-32s on hand in 1/2- to 3/4-inch lengths. The plate’s added thickness won’t demand longer screws unless you’re stacking multiple rings.

Installation experience

Installation is as straightforward as it gets:

• Confirm you’ve got a 4-inch box with corner screw tabs.
• Make sure all splices are complete, wire nuts secure, and a pigtail ground is tucked properly.
• Start the two 8-32 screws into diagonal corners.
• Hang the cover on the keyholes, slide into position, and snug the screws.

The plate covers the entire opening with a little overlap, so even slightly out-of-square framing or a rough drywall cut disappears. If you’re covering a box in a finished space, you can align the plate with the framing and it will still catch the box tabs just fine. On painted surfaces, I recommend a quick wipe of the plate before install. Mine came clean, but galvanized steel sometimes ships with a light oil film; a degreaser rag takes care of it.

Because the plate is thicker than cheap blanks, it doesn’t “oil can” when you tighten the screws. Snug is enough; no need to put your wrist into it.

Safety and code considerations

Blank covers like these exist to keep junctions enclosed, protect against accidental contact with live conductors, and maintain a continuous grounding path with metal boxes. These plates do all three. They’re conductive, so the cover bonds through the screws to the metal box. The coverage is full with no cutouts or raised device areas to fuss with, which is exactly what you want on a junction-only box.

The usual reminders apply: the junction must remain accessible; don’t bury the box behind drywall or inside cabinets. If you’re in a jurisdiction that’s picky about labeling splices (lighting vs. receptacle circuits), a Sharpie on galvanized steel is legible and sticks well.

Wet and damp locations

The galvanization provides corrosion resistance, but that alone doesn’t make a box assembly weatherproof. For exterior walls or true wet locations, you still need a listed outdoor box, a gasket, and a weather-rated cover solution. Where these covers make sense outdoors is under roof in protected porches, garages, and sheds, or inside damp basements where occasional humidity is a factor. In those scenarios, they’ve held up fine for me.

Durability over time

Beyond the corrosion performance, I look at how covers behave after a few service calls. Cheaper blanks bend or dish when you pop them on and off repeatedly; threads wear a groove around the hole and you end up with a cover that never sits quite flat again. The Qlvily plates have enough stiffness to avoid that. I pulled and reinstalled one plate five times while making changes to a low-voltage chase in a garage; it remained flat, and the keyholes didn’t elongate.

Aesthetics

You’re not buying a blank utility cover for its looks, but neat work still matters. The finish is consistent across the set, with no stamping marks or waviness that would telegraph under bright light. The edges are clean enough that you can install these in visible utility spaces without feeling like you cut a corner.

Value and who it’s for

Sold in a three-pack, these hit a nice middle ground for DIYers and small shops. If you’re a contractor burning through dozens of covers a week, you’ll probably save a few bucks buying in bulk locally. For everyone else, having a small stack delivered and ready to go is worth it, and the quality is as good as what I pull off the shelf from the big-box electrical aisle.

The thickness and galvanization mean you’re not trading price for flimsy metal. They’re reusable, they don’t warp easily, and they pair with standard hardware you already have.

Quibbles

• No screws included in my pack. Not a dealbreaker—most boxes ship with them—but it’s worth noting if you’re covering older, screw-less boxes.
• These are strictly 4-inch covers. If your job mixes in 4-11/16-inch boxes, you’ll need to keep both sizes on hand.
• The finish is a practical matte galvanization, not a polished plate. For exposed finished interiors where aesthetics matter, you might want a painted blank instead.

None of these are functional problems, but they’re worth planning around.

The bottom line

The Qlvily 4-inch galvanized covers are sturdy, correctly sized, and easy to work with. They sit flat, line up with standard corner tabs, and the keyhole-style mounting makes install and service quick. The galvanization has handled damp environments in my testing without complaint, and the thicker steel resists the bend-and-bow you get from bargain covers.

Recommendation: I recommend these covers for anyone needing reliable 4-inch square junction box blanks—homeowners tidying up open boxes, DIYers finishing a basement, and pros who want a rugged, no-drama plate for garages, sheds, and utility spaces. They’re not a specialty product, and that’s the point: they solve a common problem cleanly, with solid material and accurate fit, at a fair price for a convenient three-pack.