McNichols Metal Grating and Mesh: A Quality Inspector Answers the FAQs

I'm a quality inspector at McNichols. I review metal grating and mesh orders before they ship—roughly 200 to 300 orders a year, maybe 250, I'd have to check the system. In our Q1 2024 audit, coating and edge defects were the top reason we sent a delivery back. We rejected about 2% of first deliveries in 2024—not a number I'm happy about, but catching it here beats catching it on the job site. These are the questions I keep answering, plus a few search terms that land here by accident.

What's the difference between McNichols metal grating and McNichols mesh?

From the outside, both look like “metal with holes.” The reality is different. Grating is the heavy-duty member: parallel bearing bars with cross bars welded underneath. It carries people, pallets, forklift traffic, and spans between supports. Mesh is wire-based—woven or welded—and it's much lighter. It screens, guards, filters, and protects. They both have holes, but they're not interchangeable. If you need to support a load, you need grating. If you need airflow or visibility while stopping larger objects, mesh is usually the one.

Is McNichols mesh a screen protector?

If “screen protector” means a protective screen over a window, vent, or machine opening, then yes. Stainless steel wire mesh and perforated screens are used for exactly that: they keep debris and fingers out while letting air and light through. If you mean the glass screen protector on your phone, no. That search is more common than you'd think. To be fair, the wording is easy to trip over. I'd rather say that plainly than have someone order a mesh panel expecting a phone film.

What should I look for in McNichols metal grating for a walkway?

Start with load, not price per square foot. Most buyers focus on unit price and completely miss bearing bar size, spacing, and finish spec. Those are what decide capacity and service life. For walkway grating, I use the load tables in the current NAAMM MBG 534 manual. Those tables are based on material yield strength and include safety factors—they aren't just marketing numbers. As of January 2025, that's still the reference I check before a job gets my approval.

One lesson from experience: if a table says a size works but the unsupported span feels long, check deflection and impact. It costs a little more to go to the next bar size. A failed section costs a lot more.

Which finish should I choose for outdoor metal grating?

Hot-dip galvanized is the default for exterior carbon steel in most industrial work. The coating thickness spec I check is ASTM A123/A123M—it varies with steel thickness, so “galvanized” alone isn't a complete spec. For coastal areas or frequent chemical washdowns, stainless is usually better. Aluminum is a lighter option, but a steel bar and an aluminum bar with the same dimensions are not the same strength. If you're unsure, describe the environment: a saltwater dock is different from a dry warehouse.

Can McNichols cut grating and mesh to size?

Yes, cut-to-size is a normal part of the order. But there's a difference between a rough cut and a piece fabricated to fit a tight opening. If you need notches or exact tolerances, make sure the drawing shows them. I remember a rush replacement we had to approve in less than 24 hours. Normally I'd double-check squareness and camber before giving a thumbs up. There was no time, so we trusted the original spec—and it fit. That doesn't always happen. Measure twice, and tell us which dimensions are critical.

Can I use glass cleaner on fiberglass grating?

Not my first choice. Glass cleaner is made for glass, not for fiberglass reinforced plastic grating. Ammonia-heavy or solvent-heavy formulas can dull the gel coat over time. A mild detergent and water is the safe default. If you're cleaning oil or grease, check the resin supplier's chemical resistance guide and use a compatible degreaser. We've seen an aggressive “cleaner” take the shine off a panel and start to roughen the surface. That's a warranty claim no one wants.

How do I make brown paint to touch up scratched metal grating?

Yes, you can mix red and green or blue and orange to make brown. But the color isn't the point. The coating is the protection. If the grating is hot-dip galvanized and gets scratched in shipment, use a zinc-rich touch-up—not a general-purpose brown paint. If it's powder-coated or epoxy-coated, order the touch-up kit from the coating supplier. For a custom brown finish, send a chip back to the lab. Homemade brown paint won't have the corrosion inhibitors the original coating has.

When should I have an engineer review the design instead of just ordering a catalog product?

Whenever the platform is elevated, carries unusual loads, or is part of an egress path. I can verify specs and finishes, but I'm not a structural engineer. A stamped approval belongs on a PE's letterhead, not mine. That's a professional boundary I'm comfortable with. A supplier who says “one size works for everything” without reviewing load path or deflection isn't doing you a favor. For example, OSHA 1910.29 requires guardrail top rails to withstand a 200-pound concentrated load. That's a design requirement, not a sales bullet.

What's the most common quality issue you catch before shipping?

Coating issues at cut edges and burrs on stainless or aluminum mesh. When steel is cut, the edge becomes bare unless it's treated. In our Q1 2024 audit, coating thickness was the top reason a metal grating order went back for rework. Burrs on mesh are the close second. A burr isn't just sharp—it can scratch adjacent panels in transit and ruin the finish. That's the kind of problem that never shows up in an online photo, but it's the first thing you feel on the job site.