Hey folks, if you’ve ever shopped around for cold rolled steel (CRS) – and chances are, you have, even if you didn’t know it – you’ve probably stumbled on the same question over and over: can this stuff actually be welded? As a guy who’s been running a small cold rolled steel supplier for like 12 years now, I get it. I’ve had builders, hobbyists, and even other metal suppliers hit me up panicking because their last weld on CRS turned wonky – cracking, bubbling, or just plain falling apart. Let’s cut through the noise here, no stuffy engineering jargon, just real talk about what works and what doesn’t when it comes to welding cold rolled steel. Cold Rolled Steel
First, let’s keep it simple: what even is cold rolled steel, anyway? I know a lot of people mix it up with hot rolled steel (HRS), and that’s half the problem with the welding confusion. Hot rolled is rolled at super high temps (like above 1700°F) so it doesn’t work-harden much – it’s soft, easy to bend, weld, all that. Cold rolled? It’s hot rolled steel that’s been re-rolled at room temp after cooling. That’s where the name comes from, duh. That extra rolling does two big things: makes it way smoother, tighter tolerances, shinier, and way, way harder and more brittle than hot rolled. That work-hardening (metals nerds call it strain hardening, but we’ll stick to work-hardening) is what makes CRS so great for things like car panels, appliance frames, or metal shelves that need that crisp, smooth finish – but it’s also what gives people headaches when they try to weld it.
So back to the big question: can you weld it? The short answer is YES – but only if you do it right. A lot of bad welds on CRS don’t happen because the metal’s broken; they happen because people treat it like hot rolled, and that’s a huge mistake. I’ve seen guys bring in parts they tried to weld with a basic MIG welder, just cranking up the voltage like they would on HRS, and end up with a weld that cracks before they even lift the clamp. Why? Because CRS’s work-hardened structure hates rapid heating and cooling, which is exactly what welding does. When you heat it fast with a weld, the area around the weld (called the heat-affected zone, or HAZ) loses that tight, hard structure – wait, no, actually it changes it. The cold rolled’s grain structure is stretched tight from the rolling process; heat that grain up too fast and it can rearrange into something brittle, or cause residual stress that cracks the weld or the base metal later.
Now, let’s get to the methods that actually work. From my 12 years of selling CRS to welders and fabricators, the most reliable ones are MIG, TIG, and sometimes stick welding – but with rules. MIG is by far the most common because it’s fast, good for both thin sheet and thicker plate. But here’s the trick: you can’t use regular steel MIG wire like you would on hot rolled. You need low-hydrogen wire, or better yet, a wire specifically for cold rolled – like ER70S-3, but make sure it’s the type that minimizes that residual stress. Also, don’t weld it straight out of the package if it’s been sitting around with oil or mill scale on it. Wait, mill scale – that’s the dark, crusty stuff on hot rolled, but CRS has a super thin oil residue from the rolling process to prevent rust. If you weld over that oil, it burns and creates bubbles in the weld, which makes it weak. So always clean the weld area with a wire brush, acetone, or even sandpaper before you start. I tell all my regular customers this; half of them didn’t even know the oil was there until I pointed it out.
TIG welding is more for precision work, like custom metal art or small parts, right? It’s great for CRS because it gives you way more control over the heat, which is exactly what CRS needs. Since you can crank lower heat settings without messing up the weld, you avoid that HAZ brittleness way more than MIG. Just make sure you use the right filler rod – ER70S-2 works well here, it’s got deoxidizers that help with CRS’s slightly higher carbon content. Wait, speaking of carbon: CRS has between 0.05% and 0.25% carbon, depending on the grade (like 1018 is the most common, that’s our top seller). Higher carbon means it’s more prone to cracking, so TIG’s slow, controlled heat is perfect for that.
Stick welding? It’s doable, but only for thicker CRS (like 1/4 inch or more) and if you use low-hydrogen electrodes (E7018 is the go-to here). Thin CRS with stick welding is a disaster because the electrodes put out too much heat, and you’ll burn through the sheet before the weld even forms. I usually tell hobbyists to skip stick for CRS unless it’s a thick, heavy-duty project.
Now, what about the big mistake people make: preheating? Wait, do you need to preheat CRS? Short answer: only if you’re welding thick CRS (over 1/2 inch) or working in super cold temps (like below 40°F). Preheating slows down the cooling rate of the weld, which reduces that residual stress and prevents cracking. For thin sheet CRS (like 16 gauge, which is used for metal cabinets or ductwork), preheating is overkill – just take your time, don’t rush the weld. Post-heating, or tempering, is another trick I recommend for thicker parts. After you weld, you can heat the area around the weld to 300-500°F with a torch, then let it cool slowly in an insulated blanket. That relieves stress and makes the weld way stronger, less likely to crack later.
Let’s talk about common problems, because I’ve fixed so many of these for customers. The #1 issue I see is weld cracking – usually happening a day or a week after the weld, not right away. That’s the residual stress from welding CRS wrong. The metal was work-hardened, you added heat too fast, so when it cools, it contracts unevenly, pulls the weld apart. Another big one is porosity – those tiny bubbles in the weld, from that leftover oil on the CRS surface, like I said earlier. I had a customer last month come in with a batch of shelf brackets he’d welded, and they were leaking at the welds when he tried to paint them. Turns out he’d welded the oily side, and the bubbles made the welds porous. A quick wipe-down with acetone fixed it, no more leaks.
Wait, what about galvanized cold rolled? No, wait, galvanized is hot dipped, but sometimes people confuse cold rolled with galvanized. No, CRS is uncoated usually, unless it’s pickled and oiled, which is the standard. Another thing: don’t use too high of heat input. That’s a fancy way of saying don’t keep the welder in one spot too long. CRS is thin, so moving the torch or MIG gun steadily is key. If you pause, you’ll burn a hole, or create a big HAZ that’s brittle.
Now, as a supplier, what do I do to make this easier for my customers? I don’t just sell them a pile of cold rolled steel and send them on their way. I send every order with a little one-page cheat sheet: how to prep the surface, which welders work best, the right wire, tips to avoid cracking, and what to do if they run into issues. A lot of small suppliers won’t do that, but I’ve been in this game long enough to know that if my customers’ projects fail because they welded my steel wrong, they won’t come back. Last year, a guy who builds custom grills hit me up because his first batch of grills had welds cracking, and he’d bought from a big online supplier that gave him zero tips. I sent him a sample of ER70S-3 wire, plus the cheat sheet, and now he’s my biggest bulk customer. That’s the stuff that matters more than just selling steel.
Wait, can you weld CRS for structural projects? Like building a deck frame or a small shed? Yeah, but make sure you use the right grade. Grade 1018 is good for structural stuff, just make sure you follow the preheating rules if it’s over 1/2 inch, and use the correct filler. Don’t try to save money by using cheap wire – low-hydrogen wire is a little more expensive, but it makes a weld that’s 2-3 times stronger. I tell everyone: skimp on wire, skimp on your weld, end up with a failed part.
What about post-weld finishing? Do you have to do anything special to the weld on CRS? No, not really. You can grind it, paint it, powder coat it, same as any other weld. Just make sure you clean off any weld spatter first – that’s the little metal blobs that splatter during welding, which can rust if left on. A wire brush or a grinder takes care of that easy.
Let’s address a myth I hear all the time: “Cold rolled steel can’t be welded as strong as hot rolled.” That’s not true if you do it right. I’ve had customers test welds on CRS vs HRS, and when they use the right method (low-heat input, correct filler, preheating for thick material), the CRS weld is just as strong, if not stronger, because CRS’s base metal is harder. The only difference is the finish – hot rolled’s weld might be a little rougher, but CRS’s smooth finish stays, which is why it’s better for things where looks matter, like appliance panels or furniture.
Now, if you’re new to welding CRS, what’s my advice? Start thin. Practice on scrap CRS first – I sell small 12×12 inch scrap pieces for $2, and I always tell beginners to buy a few of those before they use good steel for a project. Try different heat settings on the scrap, see what works for your welder. A lot of new welders crank the voltage too high at first, and that’s why they burn through or get bad welds. Take it slow, move steady, prep the surface, and use the right wire.
If you’ve tried welding CRS and had a bad experience, don’t blame the steel – blame the method. I’ve seen guys with brand new $2000 welders mess up CRS because they treated it like hot rolled, and guys with basic $300 hobby welders make perfect welds on CRS once they follow the rules. It’s not about the equipment, it’s about knowing how CRS behaves.
At the end of the day, cold rolled steel is one of the most versatile metals out there – great finish, easy to form, strong when welded correctly. The whole “can it be welded?” thing is just a matter of following the right steps. If you’re working on a project and need CRS, or if you’re having trouble with a weld on your current CRS, hit me up. I’ve got all the grades, scrap pieces for practice, and that cheat sheet I mentioned earlier. I don’t do the big corporate sales pitch – I’m a small guy who’s been in this business since 2011, and I’d rather help you get your project right than make a quick buck. Shoot me a message, tell me what you’re working on, and we can work out the right steel and tips for you.
Now, before I wrap this up, let’s keep it real: I’ve made mistakes too. Early on, I sold a batch of CRS to a builder who was doing a custom gate, and he didn’t preheat the thick 1-inch plate, so his weld cracked. I gave him a discount on his next order, and I added a preheating note to my cheat sheet for thick material. That’s part of running a good supplier – owning up to the mistakes and making sure your customers don’t have to.
Engineering Steel Plates Welding CRS isn’t rocket science, but it’s not just plugging in a welder and going either. Prep the surface, use the right method, watch the heat, and you’ll get perfect welds every time. Whether you’re a hobbyist making a metal sign, a builder putting up a shed, or a fabricator making appliance parts, CRS welded right will hold up for years. Don’t let the myths scare you – it’s totally weldable, as long as you do it right.
References
- "Welding Cold Rolled Steel: Process and Best Practices". American Welding Society, 2022.
- "Metallurgy of Cold Rolled Steel". Steel Market Update, 2021.
- "Welding Guidelines for Structural Carbon Steels". American Institute of Steel Construction, 2020.
Kennen Steel International Co., Ltd.
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