On occasion, I need to cut aluminum stock, both 1.5" x 1.5" x 1/8" angle stock and 1" x 1/4" flat stock.
I have always used one of those metal-cutting wheels in my 10" Delta Miter Saw, similar to this:
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The other day, I was watching "How It's Made" and they showed the process used to make Carbide Tips saw blades. They started with the raw steel and followed the process through to the final product.
At the end of the segment, they showed a carbide-tipped blade in a miter saw cutting through a steel rod with the voice over saying something like:
"And when they're finished, they're strong enough to cut through the steel that they are made from."
Somehow, I'm reluctant to start using my carbide tipped blades to cut my aluminum stock. The thought of the teeth grabbing the angle iron just scares the bejesus out of me. But if they can be used to cut steel, aluminum should be a breeze.
Am I right to be afraid, be very afraid?
Are the cutoff wheels, even with the melting and subsequent filing/ grinding that I have to put up with, still the best option?
I've been using a 10" 40 tooth carbide saw in my old radial arm saw to cut aluminum stock with no problems, I have cut stock up to one quarter inch thick with no problem. Never get to use anything heavier. It does make a lot of noise.
I have used radial arm saws - with the cut-off wheels - to cut steel plate, but I've done it by dragging the blade over the material at ever-increasing depths.
I don't have a radial arm saw in my shop so the miter saw is my tool of choice.
I'm just curious as to whether I'd get a smoother cut with a carbide tipped blade and if it would be safe to use on angle iron, especially as to how the spinning teeth would first make conact with the upright portion of the angle iron.
Machine shops cut aluminum with 10" carbide sawblades ALL the time! On my RAS, I've cut 1.5" alum plate, with ease, stacks of 2x2x1/8 alum angle, 1/4 plate by the boatload, you name it..
They even show that shit POS Dual Saw (a hobbled circular saw), going through 1/8" alum. They make a BFD out of it, calling it "diamond plate", leading the shop-unsavvy viewer to believe it's diamond hard, not realizing its fukn
6061 alum with a tread pattern. goodgawd.....
You don't know whatcher missing!!! Your miter saw/carbide blade is *tailor made* for alum! Any tpi will do, just be more gentle if using a very course blade. Fine blades will weld up a little more, but no biggie.
Some people like to use wax, as, depending depending, the alum *can* weld between teeth, but it's easy to break out, and water is good too. I usually don't use anything, just don't push as hard as if I had coolant.
Next, that abrasive wheel is undoubtedly for FERROUS metals. It must be a BEAR to cut alum with that!!! In fact, I've never heard of an abrasive wheel even made for non-ferrous, as toothed blades are so efficient.
They DO make **grinding** wheels for non-ferrous, tho, which are very cool to use. For angle grinders, poss. for bench grinders as well.
Just use good shop sense when cutting. If using an RAS, best to push the blade IN (conventional cutting), must safer, no sudden grabbing. In a miter saw, just have the material up against the stop, in a way that minimizes the blades ability to "lift" the material.
There's a video somewhere of a shop teacher cutting like 4" alum plate with a 7 1/4" circular saw!!! Holy shit.....
As far as using these blades for ferrous (even rebar), I wouldn't do it -- the sfpm is just not right for the material, you'll wind up chipping/dulling the carbide. It CAN be done, just not with any economy of tooling.
I cut up to 1/4 inch aluminum often. Most of the time on a miter saw with a
60 or 80 tooth carbide blade. Angle stock no problem. CLAMPED DOWN TIGHT. GO SLOW. Smooth cuts. Blade will dull in time. I use the cheap Harbor Freight 10 inch blades for this. I even cut on regular band saw with wood cutting blades the thinner stuff. Blade will dull in time. But it works for me. WW
Rotate the angle iron so the angle portion is up-most and both edges are down, against the table. /\ / \ like that, only obviously the angle shows incorrectly in text. Then the blade never has an uncut edge to hook into, plus the end of the cut is done near the table. Feed slowly and consider ear protectors if you have to do more than a minute's work with it.
Ferrous materials (iron, NOT steel!) can be cut with carbides, but not hardened steel and other types; they should have made that abundantly clear as it would be possible to end up with a lot of tiny pieces of carbide (teeth) being flung all over your shop. I'd avoid anything except thin sheet steel on a carbide blade. And put it between two pieces of wood unless you want a really messy cut. They have the power of a .22 shell when the blade is at speed. And if you're not careful it can create enough heat to permanently warp the blade too, especially the cheap one with stress still in them; heat will release that stress by bending the blade.
The key is to use the right blade for the purpose -- this includes material, thickness, shape, and the tool in which it is being used.
To simply take any woodworking carbide-tipped blade and expect to use it on any general metal (ferrous or non-) _IS_ reason to be very afraid.
OTOH, there are blades for virtually any application readily available; you simply have to look for them (and, of course, know something about what it is you intend to do with it).
The key thing for safety is that the grind and particularly the hook angle be suitable for the material thickness and shape--generally that's what gets you in trouble in using a woodworking blade for metal; they're too aggressive on the hook angle and do grab or "get away" before you can prevent it. That's what the abrasive wheel prevents as it doesn't actually have teeth.
has a nice selection menu system online for selection of nonferrous blades; they don't (or at least didn't last time I looked) have ferrous blades selection online.
Amana Tool and the other major manufacturers all have a lot of useful information on blades for all purposes and what styles of tooth, etc., are good for what.
Not always if you'll look at what is available for your specific needs--in fact, I'd venture probably "no" altho again it'll depend on what you have to use one in as well as what you want to do mostly.
Thanks for all the tips (and confidence) as far as using carbide tipped blades. I'll try it this weekend.
Next question:
re: "I even cut on regular band saw with wood cutting blades the thinner stuff."
I often need to round off the ends of the 1" x 1/4" flat stock, essentially turning 6" rectangles into 6" hockey rink shapes.
I usually nip off the corners on my band saw, then use my bench grinder to rough out the rounding and finally clamp sets of 4 in a bench vise and even them out with a hand file.
Is there a special type or grade of grinding wheel that would give me the smoothest finish or any other suggestions to reduce the labor?
The "dry cut" saws (~$500) that use a carbide toothed blade to cut metals including steel run at a much lower RPM than a standard table saw or RAS. The true "cold" saws ($1,500+) that cut steel with a carbide toothed blade run are really low RPM and use coolant. You can get away with the regular saw for aluminum since the higher blade speed is ok there.
I don't cut a lot, but I've been cutting aluminum angle off and on for a few years (after someone recommended it here), using a carbide tipped wood cutting blade (40 tooth I think) in a Delta 10" miter. It cuts so fast that heat is not a consideration, so a slow RPM is not needed like with steel. I've never had a problem with it grabbing. Cut corner-up as someone else suggested. I mostly cut aluminum angle to make small L-brackets at a fraction of the price I can buy them for (looking good is usually not important).
fwiw, we had a hydraulic water-cooled machine, essentially a fancy chop saw, for cutting alum bar. Iirc, it went through 3" round bar in somewhere between 10 and 20 sec. Holy shit.... In principle, our chop saws/RAS are/do the same thing, just slower.
Not a cold saw. We had one of those, two speed: slow and slower. Very expensive blades, very accurate, centering vise, A Thomas, iirc. Repeat cuts within .005.
This was a Kalamazoo, a real *screamer*, very high rpm, special vise that held the drop side, so no material would fly off. If the coolant wasn't aimed properly (fairly high pressure water), you would get welding to the blade.
A cold saw could never get through 3" alum in 20 secs or less -- at least a traditional cold saw..
This screaming Kalamazoo put the whole shop on edge.
a "cold saw" is vastly superior to an abrasive wheel for cutting aluminum - and if you use a disk for aluminum, NEVER use it for steel- and vise versa. It is not a LIKELY outcome, but the POSSIBILITY of a Thermite explosion dictates that you keep the two separate.
A carbide blade cuts aluminum very effectively but be sure the chips do not get into the cooling air of the saw motor - chips will short the armature VERY easily - and permanently. I damaged my good Rockwell saw doing that.
Get a blade DESIGNED for cutting steel - it is a different carbide than that used for wood/aluminum. My regular carbide blade DID make short work of the mechanism of my old WorkMate when I lost track of where the blade was going, but anything heavier would likelyu have damaged the blade.
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