McNichols Aluminum Grating and Plank Grating: A Quality Inspector's Checklist Before You Order

If you're specifying McNichols aluminum grating or McNichols plank grating for a platform, walkway, or drainage cover, this checklist is for you. I'm the quality/compliance manager at an industrial materials distributor. I review every grating order before it reaches customers—roughly 200 unique items a year. I'm not an engineer, so I can't speak to load calculations. But I can tell you exactly what I check before I approve an order.

There are five steps. Follow them in order. The last one is the one most people skip.

Step 1: Confirm the Product Family and Part Number

McNichols doesn't sell grating the way retail sells boxes. There are multiple product families: aluminum grating, steel grating, fiberglass grating, and within aluminum you have various bar types and spacing. Plank grating is different from standard serrated grating.

Start by confirming:

• Bearing bar spacing
• Cross bar spacing
• Panel dimensions and orientation
• Surface style: serrated, smooth, or plank top

If the part number doesn't match the drawing, stop. Don't make it work. The part number is the contract. A mismatch here has cost us entire reorders.

Step 2: Verify the Alloy and Finish

Aluminum grating is not one material. For most structural grating, you'll see 6061-T6. Sometimes you'll get 6063. They're not interchangeable when you're calculating strength or corrosion resistance.

I once skipped verifying alloy on a resale order because the PO said 6061-T6 and the warehouse rack said the same. I thought, what are the odds? Then the cert came back 6063. We caught it before shipping, but it took two days to sort out. Now I check alloy on every single order. It's not because I don't trust people. It's because trust but verify is the only reliable process.

Finish matters too. Mill finish, anodized, or painted? For outdoor wet areas, specifying the right finish is not cosmetic. It's lifecycle cost.

Step 3: Measure Dimensions and Tolerances—Don't Trust the Label

Pull a tape measure. Check the bearing bar depth and thickness. Measure length and width at the center, not at the end. Check diagonal for squareness. If it's out of square, you'll fight it on installation.

McNichols publishes tolerance tables for grating as of January 2025. The exact values depend on product line and panel size. Don't rely on memory. Verify current specs at mcnichols.com before you order or write an inspection checklist.

Here's the thing: a panel can be within tolerance and still be wrong for your opening. Most of our field callbacks are because someone ordered a standard panel and assumed it would fit a 36-inch opening. It didn't. Measure your actual opening, and order to those numbers, not the other way around.

Step 4: Inspect Edges and Welds (The Step Everyone Skips)

This is the step that catches the most defects. A panel can have perfect overall dimensions and still fail inspection because of a burr, a sharp edge, or grind marks that broke the coating.

In our Q1 2024 quality audit, 14% of first deliveries needed rework. The biggest category wasn't dimension errors. It was edge and weld defects. On aluminum grating, that matters because bare aluminum edges can corrode in salt or chemical environments. On plank grating, a raised burr can catch a boot or scratch a forklift tire.

Run your hand along the cut ends. If it catches, it needs deburring. Inspect welds at cross-bar intersections. Look for spatter, cracks, or incomplete fusion. This is especially important for safety-critical walkways.

Most suppliers have quality processes. But most isn't all. The ones who want your repeat business will let you inspect before they ship.

Step 5: Request Certifications Before You Pay, Not After

If this is for anything structural or fall-protection related, you need material certifications. Mill test reports, alloy verification, maybe load documentation depending on configuration.

Ask for the certs at the quote stage. A vendor who hesitates when you ask for paperwork is a red flag. Not because they're trying to hide something—maybe they're just disorganized. But disorganization in documentation usually shows up in the product too.

People think expensive vendors deliver better quality. Actually, vendors who deliver quality can charge more. The causation runs the other way. The price difference pays for verification, traceability, and not having to redo it.

Common Mistakes to Avoid

Here are the mistakes I see most often, in order:

1. Ordering by a picture instead of a drawing.
2. Assuming plank grating orientation doesn't matter. It does: the plank surface is directional.
3. Forgetting to specify the bearing bar direction relative to the support.
4. Not checking the tolerance on the opening before ordering the cover.
5. Transporting grating panels flat on a truck with no dunnage, and then blaming the manufacturer for bent panels.

Transportation is one of those things that sounds like a joke until you see a 10-foot panel with a permanent bow. I should add that the vendor's packing method matters, but so does the trucking company's handling.

When This Checklist Doesn't Apply

Let me be honest about boundaries. I'm not a structural engineer. If you need load calculations, that's not the grating supplier's job—it's a licensed PE. What I can tell you from a quality perspective is how to verify that what you ordered meets what was specified.

My experience is based on about 200 mid-sized industrial and commercial orders. If you're doing something highly unusual—say, a custom cantilevered screen or a one-off architectural feature—my checklist still works, but you may need additional verification from the manufacturer.

And if you ended up here because your search was shower head with hose, white kitchen cabinets, or how to change wallpaper on mac—this isn't the article for you. I don't do plumbing, cabinetry, or desktop wallpaper. I'm a grating quality guy. That's the whole lane.

Bottom line: aluminum grating and plank grating are straightforward when you treat them as engineered components, not building materials. Confirm the product family, verify alloy and finish, measure the actual panel, inspect the edges and welds, and get the certifications before you order. Specs. Certs. Inspection. Done.

Do that, and you'll avoid the most expensive phrase in construction: redo it.