How to Use the McNichols Grating Catalog (Without Getting Overwhelmed)

Who This Guide Is For (And Why You Need It)

If you're a contractor, engineer, or facility manager who's ever opened the McNichols catalog and felt like you needed a map and a machete, this is for you. The catalog is comprehensive—maybe too comprehensive when you're under a deadline. I've been in quality control long enough to see the fallout when someone picks the wrong product from an extensive catalog. It's not pretty.

This guide gives you a four-step checklist to go from "I need a grate" to the correct part number, every time.

Step 1: Define the Load, Not Just the Opening

This is where most people go wrong. They measure the hole in the floor and order something that fits. That's step two. Step one is knowing what's going to walk, drive, or sit on that grate.

McNichols catalog specs are grouped by load capacity. You'll see terms like "A-60" or "I-500" in the bar grating section. These are not optional suggestions—they are engineering classifications. I'm not a structural engineer, so I can't tell you exactly which classification you need for a 40-ton forklift path. What I can tell you is the mistake I see most often: people skip this. They pick a standard-duty grate for a heavy-traffic area because that's what was in stock at the distributor. Six months later, I'm reviewing warranty claims on bent grating.

Checkpoint: Before you open the catalog, write down the maximum weight per square foot your grate will see. A pedestrian walkway is not the same as a loading dock.

Step 2: Understand the Material-Environment Match

McNichols offers steel, aluminum, stainless steel, and fiberglass grating. The catalog has helpful icons for corrosion resistance, fire rating, and slip resistance. Use them.

Here's a pattern I've seen more than once. Someone orders carbon steel grating for a chemical processing area. Why? Because the carbon steel price was right. The catalog says "carbon steel" but they didn't check the "corrosion resistance" rating. The result: rust within weeks. That quality issue cost a client a $22,000 redo and delayed their project launch by two weeks (unfortunately).

The fiberglass section in the catalog is particularly worth a close look if you're in a corrosive environment. It's pricey, but in my experience, the total cost of ownership is often lower than replacing rusted steel every few years.

Checkpoint: Match the material to the environment, not just the budget. Stainless or fiberglass upfront often means less headache later.

Step 3: Read the Fine Print on Bearing Bar Spacing

This is the detail that gets overlooked 9 times out of 10. Two grates can look identical but have different bearing bar spacing—and that changes the load rating and the opening size.

In the McNichols catalog, you'll see specifications like "1-3/16" x 3/16" at 4" centers." The "at 4" centers" is the critical part. That's the center-to-center distance of the bearing bars. If you pick a grate with wider centers for a pedestrian area, heels get caught. If you pick one with narrower centers for a drainage application, you'll get clogging. I said "read the fine print" and I meant it.

I ran a test with our project team once. I handed them two gratings that looked the same. One had bearing bars at 4" centers, the other at 6" centers. Only 60% identified the difference in a visual inspection. On a 50,000-unit annual order, that's 20,000 units that could be wrong. The cost difference on that order was significant.

Checkpoint: Verify bearing bar spacing against your application requirements. Don't assume "standard" is right for you.

Step 4: Verify the Part Number Against Your Checklist

You've picked a material, a load class, and the right bearing bar spacing. Now you have a part number. Don't order yet.

McNichols part numbers are encoded. The catalog tells you what each segment means, but it's easy to misread. I keep a printed copy of their part number decoding guide on my desk. It's saved me from ordering the wrong item multiple times.

The checklist I use is simple:

• Material code: Steel, Al, SS, FRP?
• Load class: Matches Step 1?
• Bearing bar spacing: Matches Step 3?
• Surface: Serrated for slip resistance? Smooth for cleanability?
• Length and width: These are often switched in a rush order.

This gets into a pretty tedious verification territory—I'd recommend consulting the catalog's technical data pages if you're unsure. I've seen orders where just the width and length were reversed. The grate didn't fit, and the timeline was shot.

Common Mistakes to Watch Out For

Mistake 1: Mixing up serial and plank grating. Plank grating has closed sides; serial grating has open sides. They look similar in pictures. The catalog separates them, but if you're looking at a screenshot from a colleague—double-check.

Mistake 2: Forgetting about cutouts and banding. If you need a hole or a notch in your grate, think about it before you order. McNichols offers custom fabrication, but it's easier to specify it upfront than to field-modify a steel grate. I learned this the hard way when a $1,200 order needed a 6-inch notch. The on-site cut cost us an extra $300 in labor and tools.

Mistake 3: Ordering from the printed catalog without checking the online inventory. The printed catalog is a great reference, but I've found that some products listed in the PDF have lead times of 6-8 weeks when you actually order. Call or check the website for stock status. In my experience, the 48-hour promise on stock items is reliable—but custom orders are a different story.

Final Thought: The Catalog is a Tool, Not an Oracle

The McNichols catalog is one of the best in the business for selection and technical detail. But it's up to you to apply it correctly. Going through these four steps every time will save you from costly mistakes. I know this because I've reviewed the paperwork on enough wrong orders to see the pattern. If you're feeling a little overwhelmed, that's normal—it's a big catalog. Just start with Step 1, and don't jump ahead.