By David R. Crosby
Specs and Tester's Tester Comments
Photos by David Sharpe
Long before I became a builder, I used gasoline-powered portable cut-off saws in the Air Force for crash and rescue recovery work to cut through automobile and airplane wreckage and buildings. I left the Air Force long ago, but not the saws. Now I build homes in Santa Fe, N.M., and work with as much adobe, concrete, stucco, and re-bar as I-joists and OSB. My Air Force experience gave me a real appreciation for these tools, so anytime I have to cut concrete, masonry, or steel I reach for one. It also showed me that nobody in their right mind would look forward to using them?they're loud, expensive, and incredibly messy, whether wet cutting or dry. But when it comes to cutting tough materials, they're also the best tools for the job.
I tested four 14-inch-diameter saws for eight weeks with engines ranging from 64.1 to 81 cubic centimeters (cc): the Makita DPC7301, Multiquip Side Winder HS81, Partner K700, and Stihl TS 400. I cut concrete, masonry, stucco, and steel, evaluating the tools for power, looking at switches and balance, and checking for smooth blade-guard operation and easy blade changing. I also tested their wet-cutting capabilities and paid careful attention to serviceability.
Everywhere you look in Santa Fe you'll find 4-inch-thick concrete slabs, brick and block walls, 8-inch-thick concrete walls, stucco, and steel, so they're part of everything I do. From cutting out window and door openings and plumbing access to demolishing buildings, these tools play a big role every day.
Concrete and Masonry. Brick, block, and stucco were no match for all four of the tools in this test. The same is true for short cuts in a 4-inch-thick slab; however, the 8-inch concrete wall (where we buried the blades on both sides of a long cut) brought out the tools' power differences.
The Makita cut-off saw was relentless. With a 73-cc engine, it was fast, smooth, and powerful. While the 64.1-cc Stihl was a little less powerful than the Makita, it performed well in every situation. The Multiquip and Partner tools followed next. They were more reluctant in 8-inch concrete and vibrated more than the other two models. The Multiquip vibrated the most, while the Partner cut the slowest.
Steel: Angle, Re-bar, and Structural Tube. As building designs become more creative, I find I am working with more steel, which overpowers my re-bar cutter and recip saw. Cutting 20-piece bundles of #6 Grade 60 re-bar was no problem for the cut-off saws. As for pipe and tube, it took more time to block it into position than it did to cut it.
Controls, Adjustments, & Balance
The primary controls on cut-off saws are the on/off switch, choke, compression release, and throttle. I looked for them to be easy to reach and operate, and tough enough to take the abuse these tools face.
The Makita's and Stihl's controls are my favorites. I could reach and operate them easily, even with gloves on, and they all worked with positive action. The only criticism I have is that they could use a half-choke detent. The Multiquip switches are a bit small but worked fine; they also could benefit from a half-choke detent. Partner's switches worked well, too, though the plastic made me wonder how they'd do in cold weather.
Blade Guard. The blade guard is the most important safety feature on these tools. It should always be properly adjusted for the angle you're holding the saw relative to the work, and a good adjustment mechanism makes for a guard that workers will actually adjust (in my experience) rather than use the saw unsafely.
The Makita blade guard has a tool-free manual lock that works smoothly through the operating range, even when it's gunked up with slurry or dust. Next I like the Stihl's friction pad. It works like a brake pad that's always half on. It presses hard enough to hold the guard in place while you're working, but not so hard that the guard isn't easy to adjust. It's a great feature that makes for foolproof guard placement. The Partner model has a friction pad, too, and adds detents, making for both foolproof and positive guard placement. The Multiquip's friction lock knob must be un-screwed and re-tightened. It's not difficult but requires more effort.
Balance. While all the product manuals caution users not to cut with these saws while holding them above shoulder height or while you're on scaffolding or ladders, there are times when that's exactly how you have to use them, and that makes balancing these tools "out of position" a big deal.
The Stihl is an exceptional, well-balanced, mobile tool. It's the lightest saw and is easy to move into position and keep on the line, especially in a cut-out or demolition situation. The Stihl also is great for lugging over big rubble piles on large demo jobs. I like the Makita even more. It's got terrific balance, and once it's in position and cutting, it runs so smoothly I find it to be the most comfortable saw by far. Both the Multiquip and Partner maintain good balance out of position, too.
As an abrasive blade wears down, it cuts slower and forces the saw to work harder for less gain, so when you notice a significant decrease in cutting performance, change the blade. Also, don't quickly re-enter your kerf after changing abrasive blades. The new blade is thicker than the old one and can bind, potentially causing the tool to jump unpredictably.
The wheel changes on each saw are straightforward, but the Multiquip has an ingenious feature: reversible blade collars that accommodate different arbor sizes.