The Heavy Steel Checklist: 7 Questions I Ask Before Every Fabrication Order (And Why You Should Too)

The 7-Question Pre-Order Checklist for Heavy Steel Fabrication

I've been handling heavy steel fabrication orders for a steelwork supplier for about 6 years now. I've personally made (and documented) 8 significant mistakes that I can think of, totaling roughly $24,000 in wasted budget and rework. I still kick myself for a few of them. Now, I maintain our team's pre-production checklist to prevent others from repeating my errors. It’s not perfect, but it’s saved us a lot of headache.

Real talk: most problems are avoidable with a bit of up-front verification. Here’s the checklist I run through before every major order—for structural steel, bridge components, or even a metal carport with storage. It’s seven questions that cover the majority of the mistakes I’ve made (and seen others make).

1. “Is my spec actually buildable?”

This sounds basic, but it’s where I made my first big error. In 2018, I submitted a drawing for a short-span bridge with a weld symbol that, on my screen, looked fine. The fabricator called me and said, “We can’t weld this without a backing bar on that flange.” I’d specified a CJP groove weld in a gap that was too tight.

The result: 18 beams, $3,200 in rework, and a 1-week delay. What I learned: check your tolerances against standard welding practices. For example, a complete joint penetration (CJP) weld requires a root opening of at least 1/8 inch, depending on the process (Reference: AISC 360-16, Table J2.1). If your gap is less than that, you’re asking for trouble.

Now, I send my drawing package to the shop lead for a “buildability review” before ordering. It adds a day, but it’s saved us from 3 potential rework situations in the past 18 months.

2. “What is the specified steel grade and are there equivalents?”

Here’s the thing: not all steel is the same. I once ordered “A36” for a gusset plate on a heavy steel frame project. The supplier was out of A36 and offered me A572 Grade 50 as a “direct substitute” for the same price. In hindsight, I should have double-checked the weld procedure.

Why does this matter? Because A572 has higher yield strength (50 ksi vs. 36 ksi), which can change the required weld size. If you’re following a pre-qualified welding procedure (WPS) that was written for A36, using A572 might be fine—but it’s not a drop-in replacement for every joint. Put another way: check your WPS, don’t just take the supplier’s word.

Around 2021, I started adding a line to my RFQ: “Specify equivalent grade if substitution is proposed.” It’s saved me from a potential joint failure on a beam-to-column connection. (I’d have to check the exact case, but I want to say it was a 10-ton beam.)

3. “Are the coating and corrosion protection requirements clear?”

For bridge steel fabricators, this is a big one. In September 2022, I ordered a set of pedestrian bridge railings with a “hot-dip galvanized after fabrication” spec. The shop subbed out the galvanizing, but the pieces were too long for their bath. They had to do a double-dip, leaving a lap joint that corroded within 6 months.

The question is: did I specify the length limit for galvanizing? No. I assumed the fabricator would figure it out. The result: a $4,500 cost to strip and re-galvanize, plus a 2-week delay.

Now, I check the maximum piece size for my preferred coating method (like hot-dip for members over 10 feet). According to ASTM A123, the bath size is a limiting factor. If your member is over 40 feet, you might need a different approach (e.g., thermal spray).

4. “Are my connection details standardized?”

This is another one I learned the hard way. On a heavy steel structure project in Q1 2024, I designed a custom bracket for a purlin-to-rafter connection. It was fine, but the fabricator had to order a special drill bit for the 1.25-inch oversized holes I specified. That cost $120 in setup and added a day.

Look, there’s a reason standard connections exist. They’re cheaper and faster. If you're a steel frame supplier or an engineer, try to use common bolt patterns and hole sizes. For example, standard high-strength bolts are 3/4 or 7/8 inch diameter. If you use 1 inch, you might be okay, but your fabricator might have to order a special die. It’s not a huge cost, but it adds up.

These days, I try to stick to standard AISC connections (like single-plate shear connections, or bolted seat angles) unless the loading requires otherwise. It’s saved me at least $800 in tooling changes that I can’t prove, but I’m pretty sure about.

5. “What about fit-up in the field?”

For modular construction, like pre built houses or panelized steel frames, this is critical. In 2020, we ordered a set of wall panels for a small apartment project. The panels were fabricated to precise millimeter tolerances. But the foundation had a slight twist—maybe 1/4 inch out of square.

The panels didn’t fit. We had to shim every joint. It added 3 days to the schedule and about $1,200 in extra field labor. The mistake? We hadn’t discussed field adjustment tolerances with the fabricator.

Now, on every order for pre built houses or steel carports, I specify: “Field adjustability must be allowed for connections. Provide slotted holes in one direction per joint.” (think 1/2 inch slotted holes for bolt-up connections). It’s a tiny spec change that avoids a major headache.

6. “Are the testing and inspection requirements confirmed?”

I always assumed the fabricator would do the necessary NDT (non-destructive testing). In 2023, I specified “100% UT on all CJP welds” without confirming who pays for it and what standard. The shop’s standard was AWS D1.1. I wanted ASME Section V.

The result? The inspector failed the first 3 welds because of a calibration discrepancy. The cost to re-test and revise the procedure: roughly $900. And a 1-week delay.

Now, I explicitly state: “Testing to [Specific Standard] per [Client Spec]. Confirm inspection procedure and technician certification.” It seems obvious now, but it wasn’t then. If you're working on a bridge steel project, this is often code-mandated. So, verify your NDT requirements before you order.

7. “Have I physically verified the material with a sample or photo?”

I once ordered a “dead flat” base plate for a column. The supplier sent a plate that was, in my words, “flat enough.” It wasn’t. When we tried to grout it, the plate was 1/8 inch out of plane. We had to grind the grout pad, which cost $500.

Here’s what I do now: for any critical component (like a heavily loaded base plate or a cantilevered beam), I ask the fabricator to send a digital photo or a coordinate report of the finished piece before shipping. It’s not the same as a physical inspection, but it catches the obvious mistakes.

I’ve caught 3 potential issues this year using this method—a wrong hole pattern, a missed stiffener, and a surface defect. Each one would have been a field fix. The cost of a photo: zero. The cost of the fix if I hadn’t caught it: probably $2-3k total.

This might seem like overkill for a simple metal carport with storage. But I’d argue the principle applies: verify before it ships. A 5-minute check is cheaper than a site visit.

The Bottom Line (For Real)

There’s no perfect checklist, but these 7 questions have saved me from repeating my biggest mistakes. If I had used this list from the beginning, I’d have avoided at least $15,000 in rework and maybe 2 weeks of delays. That’s my estimate, anyway.

If you’re ordering heavy steel fabrication, especially for a bridge or a custom structure, take the extra hour to verify these items. It’s the cheapest insurance you can buy.