By Erik Elwell
I build in New York City where fire codes mean that metal framing is the only game in town. And because my company does so much light-commercial work (office and retail build-outs) my jobs are loaded with uni-strut, Chicago bar (also called furring channel), steel pipe, threaded rod, and even structural steel, all of which need to be cut to length like any other building material. The problem, of course, is that the same characteristics that make steel a great building material–durability, hardness, and strength–are the same things that make cutting it basically torture.
You can't flip open a window in a skyscraper, so we usually end up working in enclosed spaces where using cut-off saws with abrasive wheels will fill the air with acrid smoke and airborne filings. And if that's not bad enough, hogging through a bundle of metal studs in a closed room is eardrum-blasting at best. So, despite the fact that we're building out high-end spaces for A-list clients city-wide, we trim our studs to length with aviator snips. It's a slow and imperfect process, but it has been status quo for this town. Until now. I tested six metal-cutting circular saws for a month-and-a-half and my production went up so much during the test, there's no turning back.
I evaluated four cordless models–the 15.6-volt Panasonic EY3530NQMKW and the 18-volt DeWalt DW934K-2, Makita 5046DWDE, and Milwaukee 6320-22–and the corded Milwaukee 6370-21 and Porter-Cable 440. I used them to cut all the metal building stock we encounter every day: mountains of metal studs, uni-strut, Chicago bar, copper and steel pipe, angle iron, sheet metal, and electrical conduit. I tested how power and blade diameters matched up with the various materials we use. I looked for effective blade guards, and then focused on balance, feel, and clear sight lines during operation. Finally, I evaluated the tools according to their specific–and different–designs and capabilities, then based my conclusions on my jobsite requirements. While I looked for the same details in each tool, I evaluated the corded and cordless models in separate groups.
Power & Performance
I must admit that I was nervous the first time I watched a gleaming silver carbide-tipped blade ready to bite into a 2-inch steel pipe. The former stick-builder in me expected the blade teeth to hook the steel and rip the saw out of my hand. Instead, the saws easily sliced the steel and sailed through with a low-pitched, totally bearable scream ("bearable" assumes you wear suitable ear protection, which is standard issue on my sites). After the effortless cut, the pipe end was clean, cool to the touch, and ready to install.
Structural Material. When we do use cut-off saws with abrasive wheels, we cut our stock in bundles. Metal studs and Chicago bar come 10 to a bundle and we lop them to length, so I tried that with all the saws in the test group. Each tool in the group performed great, and they glided through the stock faster than I had hoped. All the cordless saws cut bundles of 2x2 and smaller bundles of Chicago bar in one nearly effortless pass. The larger-diameter corded saw blades sailed through as well. Larger stock, like 2x3 and 2x4 studs, required two passes from all the saws. This means that we can cut 10 studs in about 10 seconds, instead of the four-minute job it used to be with snips. The 3-5/8-inch studs also required two passes from the corded and cordless saws. Next, I cut into bundles of Chicago bar and uni-strut and all the tools delivered the same great performance. The tools made unbelievably quick work of all this material.
When I put the saws to work cutting heavy-walled pipe like black iron gas pipe and galvanized pipe, the 15.6-volt Panasonic bogged down and stopped a couple of times; the 18-volt DeWalt, Makita, and Milwaukee cordless tools had to work hard to get through, but handled it pretty well.
Both corded saws, which are expectedly larger and less nimble than the cordless tools, flew though framing and pipe without even slowing down, which makes them perfect for use at a cut-station for gang-cutting. And, if you need to cut the big stuff like 1/4-inch angle iron or 1/4-inch steel C-channel, grab an extension cord because plugging in is the way to go. While the cordless cutters can do it, it's asking a lot, sort of like expecting your cordless drill to work like your hole hawg.
Thin-Walled Pipe and Conduit. It didn't take the plumbers and electricians on the job long to catch wind of what I was doing. It took even less time for them to pick up the tools I put down and walk over to their own projects installing pipe and conduit. Typically, my subs show up with portable band saws and hack saws for fitting their runs. That's over. Each saw in the test group flew right through conduit, leaving a burr-free end, cool to the touch and ready for joining. Even thin-walled copper and steel pipe were cut easily. And, when using a speed-square as a guide, the copper is ready for fitting in a matter of seconds. Hands down, these guys wanted the cordless tools, because they are so light and portable.
Cut Capacity, Cordless. Cut capacities vary widely among the tools. Panasonic has the smallest at 11-3/16 inches, and DeWalt's has the largest at 2-3/8 inches. In between you have Makita at 2-1/16 inches and Milwaukee at 2-1/8 inches. For the work we do, all these saws got through our 2-by stock when we cut it on the flat. They also got through individual lengths of copper pipe, uni-strut, and black iron pipe. The light Panasonic stood out again here in lighter-gauge materials because it is so light and well-balanced.
Cut Capacity, Corded. Milwaukee's corded 8-inch saw has a 2-9/16-inch cut depth, enabling framers to cut 2-1/2-inch framing bundles in one pass–a smart design strategy. Porter-Cable's 7-1/4-inch blade with a 2-1/2-inch cut depth left the cutoff hanging by a hair and required a second pass. Both saws required two passes for knocking down 2-by framing bundles.
Feel, Chip Collection, & Sight Lines
Feel. Because this is a relatively new tool category, designers haven't settled on an industry standard or an optimum size for these saws, which means not only different blade diameters and cutting capacities among the tools, but also that each unit has a markedly different feel–fortunately, they're all good. If I had to choose (and I do) I'd say the DeWalt and Milwaukee cordless were a bit more comfortable to use than the other two cordless units were. Both have comfortable grips and their switches are easy to reach and engage. That said, the Panasonic and Makita are nicely balanced, too, and their switches are well-placed and easy to use. Check out these features for yourself and see which tool feels best in your hands.
Among the corded tools, I liked the Milwaukee best. The balance is right-on. The Porter-Cable feels good, too, but the ergonomics seem to be a step behind.