I found one of these things on close-out at Lowe's (because of too few buyers) and thought I'd take a chance. If you haven't seen one, they look at first glance like some kind of hopped up "skilsaw" (standard hand-held wood-cutting circular saw) or worm-drive saw. But on closer inspection you see they have dual carbide insert blades that counter-rotate side-by-side.

I'm guessing that the original motivation was to make an ordinary wood saw that reduced or eliminated kickback. That property wouldn't interest me much, since I have no big problem using the old-style saws. But it was found that the counter-rotating carbide blades will gnaw through darn-near anything, not just wood but sheet steel, aluminum, copper, and even stainless. THAT got my interest, since stainless can be a bugger to deal with unless you have a plasma cutter handy. Oh, and you can buy diamond blades for doing masonry and tile.

A curious feature is a little roller-wheel in a seemingly useless location. Turns out that is a manual thumbwheel for feeding in a lubricant stick when you are cutting metals, sort of like you occasionally had to punch the chain-oiler button on older chainsaws.

I just got this thing and haven't tried it yet. It's one of the bigger ones, with 6 1/2" blades. Have any of you found one of these to be a go-to tool for any frequent purpose?

I'm told that these were advertised on TV (I don't watch) for a while, and that the infommercial featured the saw being used to cut a car in half in about ten minutes. I'm guessing that rescue crews pulling folks out of wrecked cars would not use these because of sparks. But just imagine an ad for a local hot-rod shop, with the owner standing out front, revving up his demolition-saw, and saying, "Ya wanna top-chop? Channeling? Sectioning? Hey, we got it all covered right here!!"

www.dualsaw.com I see Harbor Freight has a smaller one, 5" blades, on sale at about $55