As a remodeler, I spend most of my days cutting wood. When I do have to cut metal, I use a grinder or a recip saw. For the past few weeks I’ve been testing Bosch’s new 18-volt CSM 180 Metal-Cutting Circular Saw and it has made me realize the downside to the methods I normally use. The Bosch saw is capable of making quick accurate cuts in materials such as steel studs, rebar, threaded rod, conduit, and Unistrut. And unlike the tools I normally use to cut metal, it produces clean cuts and does not shoot sparks all over the place.
The tool may look like a small version of a regular circular saw, but it was designed with metal in mind. Bosch stripped off features that are not necessary for cutting metal. The saw doesn’t bevel and there isn’t much in the way of marking on the depth-of-cut adjustment. The footplate is small, the front pommel handle isn’t there, and the kerf markings are minimal at best. And that’s fine, because this is a tool for cutting lengths of metal, not for notching a rafter tail. Because of the bare-bones design, is small and light—weighing in at less than 6 pounds. This makes it easy to use at or above head level. The ergonomics are good; the grip is smartly padded and comfortable to hold.
According to Bosch, the motor was designed to produce higher torque and faster initial acceleration than the motor in a wood-cutting saw. The upper half of the blade is shrouded to keep metal chips from hitting the operator. To maintain sight lines, the front two inches of the guard are clear plastic (on a wood cutting saw this part of the blade would not be shrouded). A small LED lights the cutline, which is a big help (even in well-lit areas) when you have to view the cutline and blade through plastic. The LED can be activated by tapping the trigger and not turning on the saw motor, which is good for lining up cuts.
The lower moveable portion of the guard has a metal strip on its leading edge to protect against the constant abuse of riding against metal. After a couple weeks of use, the plastic portion of the guard looks fine, but over the long term I could see it wearing down and the strip coming in handy. The only other feature on the tool is the rafter hook, which is easy to flip up and pivot around. When not in use, it folds forward and tucks into the handle. I usually had it hooked over a wire opening in a metal stud, but it is big enough for 2x material.
I used the saw to cut heavy gauge metal studs, rebar and conduit. In every case it made a nice, clean cut that was immediately cool to the touch. A recip saw makes for an inaccurate and ragged cut and an angle grinder is slow, hot, and blows sparks everywhere. I’d choose the CSM 180 every time over those other tools.
The CSM 180 has a toothed blade and not an abrasive blade, so it can also cut wood. I realize it’s not designed for that, but in a pinch it can be used to make the occasional rough cut in wood when your regular circ saw isn’t nearby. It’s also good for those times when you hop in the dumpster and consolidate what’s there. You have the convenience of cutting with a circ saw without having to worry about what happens if you hit a nail.
This saw was designed with plumbers, electricians, and HVAC techs in mind. But it would also be handy for the remodeler, who like it or not, will likely need to cut metal. As a remodeling carpenter, there are enough instances when I have to cut metal to justify the price of this saw.
Bosch CSM 180
Battery: 18-Volt Lithium-Ion
RPM: 3,800 (no load)
Weight: 5.8 pounds (w FatPack battery)
Blade diameter: 5 3/8 inches
Max depth of cut: 2 inches
Kit (CSM180-01) includes: charger, two 4.0 Ah batteries, blade, 30-tooth metal cutting blade, and carry bag.
Price: $350 (kit); $199 (bare)