Cutting aluminum with carbide wood cutting blade on tablesaw

I have a tablesaw with a sliding cutoff box that I often use to cut small pieces of wood and plastic.

Today I needed to cut some aluminum (about 3/32" thick).

I put in a steel blade that was marked "for aluminum and plastic" and had a difficult time. The cutting went slowly and the aluminum got very hot. By the end, the blade was bent.

I then put in a 40-tooth (8-inch dia.) Piranha carbide-tipped wood-cutting blade that was several years old. It cut the aluminum very happily, with very little heat.

I know this is putting more wear on the blade than wood would, but how much more? Am I doing anything harmful to the tools? Seems to me the original "aluminum and plastic" blade was much worse.

Reply to
mc
Loading thread data ...

The aircraft shop next to mine uses a chop saw with a wood-cutting blade to cut not only aluminum, but also chrome moly steel tubing. They report that with a slow, even feed the blades last for a long time.

"Very hot" means either dull blade or feeding too slowly. Carbide teeth flying around the shop indicate excessive feed speed. DAMHIKT.

-- Morris Dovey DeSoto Solar DeSoto, Iowa USA

formatting link

Reply to
Morris Dovey

proper tool for the job is a "non ferrous metals" blade - has Carbide tips with a different profile and set than the wood blade. draw your line with a candle first - the wax keeps the chips from sticking in the gullet.

*** Free account sponsored by SecureIX.com *** *** Encrypt your Internet usage with a free VPN account from
formatting link
***
Reply to
clare at snyder.on.ca

April 2006 Workbench has some information on cutting aluminum on a tablesaw. They recommend using a regular carbide blade with a zero clearance insert and also mounting the aluminum with double-sided tape to a sacrificial piece of hardboard, then usig a pushblock with a heal to push the aluminum through the blade. Workbench April 2006, pp 34 ff.

+--------------------------------------------------------------------------------+ If you're gonna be dumb, you better be tough +--------------------------------------------------------------------------------+
Reply to
Mark & Juanita

Mark,

In this context, is "heal" a typo for "heel", or something specific to cutting aluminium?

(serious question, no sarcasm intended)

Reply to
Dave Balderstone

Many thanks. I have a carefully built sliding cutoff table with essentially zero clearance, and if whatever I'm cutting is so small that my fingers would be close to the blade, I put a block of wood down on it and hold it down with that.

Reply to
mc

Don't use dust collection when cutting metal.

Reply to
Frank Drackman

I used some of the blades called nail biters, meant to cut off nails in old lumber. That worked pretty well because it had little rake, but any Carbide blade works. When I worked for someone who could afford it, we would use those radically expensive fine tooth blades and the cuts were lots smoother. We usually would just have a guy shoot a shot of WD 40 now and then.

The most important part of this job is the wearing of Gloves, Eye protection, and NEVER let off a stern grip. When a chunk of aluminum gets kicked back, things tend to hurt for a while. Use every method possible to ensure it does not kickback, and your board on the top is a good step.

Grummy

Reply to
grumtac

You are correct, it was a typo (can't believe I didn't catch that before sending). i.e, the pushblock (they recommend a 2 x 4) has a heel that catches on the back end of the sacrificial hardboard to push the hardboard/aluminum piece through the blade.

+--------------------------------------------------------------------------------+ If you're gonna be dumb, you better be tough +--------------------------------------------------------------------------------+
Reply to
Mark & Juanita

Out of curiosity, why not?

Josh

Reply to
Josh

Because you can set your dust collector on fire very unexpectedly. And may burn very hot and very vigorously with that air flow stoking it on.

Gunner

"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences."

- Proverbs 22:3

Reply to
Gunner

I have an old DeWalt 60-tooth that I've use to cut both aluminum and steel, on my table saw. (Several pieces of aluminum. One piece of 1/8" steel). Works very well. I am careful to feed the material rather slowly, and if the carbide teeth start breaking off, I'll chuck the blade. The idea of carbide pieces bouncing around my shop, does give me some pause. But so far, no problem.

Several years ago, I watched a pole barn being built. The crew used high speed steel blades, REVERSED in the skill saws to cut the metal.

THERE is no recommendation in this post. I'm just saying, I've tried it and it works for me.

"And as always, there is no more important rule than to wear these, safety glasses."

Reply to
Amused

Good point (the hardboard)...I lost a bunch of teeth on a thin kerf blade I really liked one time when a thin piece of aluminum wrapped around it :(

-- dadiOH ____________________________

dadiOH's dandies v3.06... ...a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at

formatting link

Reply to
dadiOH

It is really easy to start a fire with hot metal shavings and a pile of dry woodchips.

Reply to
Frank Drackman

wood-cutting

Any idea what the purpose of the sacrificial chunk of hardboard is? Perhaps for cutting small pieces? I can't imagine any need for one if there isn't an issue of getting one's fingers too close to the blade.

Reply to
Mike Marlow

One of the problems I had was vibration - rapid lift/contact with the table. I expect that was from the slight spring in the metal. The hardboard would add mass and dampen that.

Reply to
Rex B

That makes sense.

Reply to
Mike Marlow

That process is known as friction sawing, and is used to great advantage for sawing even heat treated items. DoAll makes vertical band saws specifically for that application, with blade speeds that exceed 10,000 FPM. One can saw with a blade inserted with the teeth running backwards equally as well as with the teeth running forward. They don't cut by the same principle as low speed machining.

Harold

Reply to
Harold and Susan Vordos

"mc"

more? Am I doing anything harmful to the tools?

Sears sells an Aluminum/Laminate triple grind tooth carbide blade that does quite well. I've cut out tons of .080 aluminum and it still cuts the same, fast and no heat.

Reply to
Humanid

When we build patio covers we cut the "C" channels, bracing, and heavy columns with a 10" chopsaw with a regular 60 tooth wood cutting blade that was retired from finish work.

I cleaned all the resin and buildup off it before using it on aluminum an it works great.

I can only imagine the same results in a table saw. No matter what though, wear your goggles. Those little aluminum chips really fly around and have sharp edges. They stick in my arm all the time and I just brush them off. But that wouldn't work in the eyes.

Robert

Reply to
nailshooter41

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.