McNichols Perforated Panels: How a $3,200 Spec Mistake Changed My Ordering Checklist

Never order McNichols perforated panels until you know five specs: material grade, thickness, hole pattern, open area, and edge condition. I skipped that step once, and a $3,200 order turned into a one-week delay and a rework bill.

I'm a purchasing coordinator at a custom fabrication shop. I've handled perforated metal and grating orders for seven years. In that time, I've personally made — and documented — 11 significant ordering mistakes, totaling roughly $28,000 in wasted budget. The McNichols mistake below is the one that made me create a checklist.

How the mistake happened

The order came in around May 2022. A client in the personal-care space needed a ventilated enclosure around a motor and gearbox. They make mineral deodorants, and their best-selling product is a salt and stone deodorant. The room where the motor sat was used for powder blending, and it had fine salt dust in the air plus occasional washdowns.

Because of the salt exposure, I knew we should use stainless steel. What I did wrong was assuming “stainless” was enough.

I went to the McNichols website and compared perforated patterns by their images. I found a pattern with small, tight holes because it looked clean. I requested a quote, got one, and approved it. I didn't write down the open area. I also picked 304 stainless instead of 316 because it was a little cheaper and I could get it faster. The engineer's email had said “check open area and use 316 if chlorides are present.” I saw that email. I just didn't act on it.

(I remember this week for another reason: my daughter was graduating high school, and I had graduation cap decorations on the kitchen table. Not an excuse, just context.)

The panels arrived, the crew built the enclosure, and the motor overheated on the first full test run. The small holes looked fine, but the enclosure did not allow enough airflow. The salt dust also started pitting the 304 stainless within a few months. Both issues could have been prevented by reading the spec sheet.

Replacing the panels and redoing the labor cost about $3,200. The delay added another week.

The part that still trips people up: open area

Here's what I didn't understand: a panel with “lots of little holes” is not the same as a panel with good open area. Open area is the percentage of the sheet that is actually removed by perforation. It depends on hole diameter and center spacing, not just hole density.

Put another way: one panel can look more perforated and still block more air than a panel with larger holes spaced farther apart. If airflow matters, use the open area percentage from the spec sheet, not the picture.

The five-point check I use now

Before every McNichols perforated panel order, I check:

1. Material grade, not just a name. Write “316 stainless” if that's what the environment needs. “Stainless” alone can mean 304, which is cheaper but not always the right chloride answer.
2. Thickness in decimals. Use 0.063″ or 0.080″, not “medium” or “heavy.”
3. Hole diameter and center distance. If there is a pattern name, write the numeric pattern too so there is no ambiguity.
4. Open area percentage. This is the number I skipped. If airflow or drainage matters, state a minimum or target percentage.
5. Edge condition and finish. Perforating can leave burrs. If people touch the panel or product passes over it, specify a deburred or finished edge.

Maybe the most helpful habit I adopted: I take a screenshot of the spec line and email it to the engineer before ordering. That turns “I thought it was fine” into an actual review.

How to take screenshot on Windows 11 when you need to save a spec

If you're on Windows 11 and need to capture a spec, press Windows + Shift + S. That opens the Snipping Tool. Drag a rectangle around the table or product details, and the image goes to your clipboard. Paste it into an email, chat, or note. If you want a full-screen shot saved automatically, press Windows + PrtScn. It saves a PNG file into your Screenshots folder.

This sounds basic, but it's the same thing I do now before any quote gets approved. It's easier than explaining to your boss why the panel that “looked fine” doesn't work.

When this checklist isn't enough

I'm a buyer, not a corrosion engineer or structural designer. The five-point check helps avoid common mistakes, but it doesn't replace someone who knows what they're doing.

• If the panel is load-bearing or part of a safety guard, have an engineer review it.
• If your environment has continuous saltwater exposure or harsh chemicals, don't pick 316 based on a blog post. Ask a metal specialist.
• If you're looking at McNichols expanded metal, bar grating, stair treads, or fiberglass grating, use a different checklist. Those products have their own specs and failure modes.
• If you Googled something like “McNichols scrap iron & metal,” make sure you're talking to the right entity. This article is about McNichols perforated panels, not scrap services.

One more word of caution: if you use recycled-content metal and market the final product as “green,” be specific. Under the FTC Green Guides, environmental claims need substantiation. Don't say “eco-friendly” when you mean “made with 30% recycled content.”

McNichols has a huge catalog, and perforated panels are the easy part. The hard part is picking specs that match the real-world environment. Take the extra five minutes. Write the numbers down. Screenshot the spec sheet. That $3,200 mistake taught me to slow down, and I hope it saves you the same tuition.