Abraisve cutoff wheels: ferrous, non-ferrous, masonry

Awl --

What's the real diff?

Can one wheel do all, to some degree? For cutting, not grinding. I"m mainly concerned with ferrous, non-ferrous cutoff wheels, but just curious as to how the masonry fits in.

If there really is a big diff between the ferrous, non-ferrous, I'd like to get a second cheap chop saw from Sears, have them separately set up -- since my 4x6 bandsaws look like they won't ever function properly again.... :( AND since it looks like I'll never find a decent blade welder.... :( :(

Oh, along these lines, I use my RAS to cut alum bar, extensively -- carbide blade. Can I also cut brass/bronze this way? As efficiently? Abrasive better?

Reply to
Existential Angst
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All I can say is that in my experience, the metal-cutting disks do very poorly at cutting concrete.

Don't know why that is...

Reply to
Home Guy

Metal cutting blades and wheels use aluminum oxide as their primary grain. Masonry and stone materials use silicon carbide. Non ferrous materials, especially aluminum, will gum up and gall on blades, files, and cutters.

According to my dad (92 year old retired tool and die maker) never use the same files or cutting tools on ferrous and non. He always contended that the use on one ruined its ability to work well on the other. I don't know that I have been that much of a purist.

Reply to
DanG

After I go through a file used to sharpen a chainsaw chain, I still find it is useful for many other things, even softer ferrous materials, but you need a *new* one to sharpen a chain.

Jon

Reply to
Jon Danniken

Probably an angle grinder with a diamond blade. I used a fibre abrasive blade in a circ saw to cut some pavers. Tremendous amount of dust in the air. Went through a couple blades, but they're cheap. A good diamond blade is probably 30 bucks. Even with a diamond blade, unless you can wet the cut somehow, you need to tent the work off and use a good respirator. Concrete varies in hardness too, so some will cut easier, some harder.

Reply to
Vic Smith

Dry diamond wheel on circular saw (might be hard to get the 1") or dry diamond on small off set grinder. There will be a lot of dust which can be minimized with water, but the resultant slurry might be worse.

Reply to
DanG

Aluminum Oxide is most commonly used for grinding and cutting ferrous metals.

Silicone carbide is most commonly used for grinding and cutting non-ferrous metals.

I was told by one guy at Norton Abrasives that he was once told that the reason for that was because when you're grinding ferrous metals, the carbon in silicone carbide can be absorbed into the iron, increasing it's carbon content, and thereby making the iron near the cut harder and more difficult to machine. So, when grinding iron or steel, he was told they used aluminum oxide to avoid that problem.

But, it turns out that he was misled. Apparantly, the absorbtion of carbon from silicone carbide abrasives has nothing to do with it. But, even though the reason given was wrong, he found that to be a good way to decide what abrasives to use on what.

So, when in doubt, think about the carbon in the silicone carbide, and know that the only difference between iron, steel and cast iron is the amount of carbon in the metal, and so you don't want to change the machining characteristics of your iron based metal by using silicone carbide on it.

That is, wrong reason, but it still gives the right answer when it comes to choosing grinding wheels.

Reply to
nestork

I have used masonry blades to cut steel when I didn't have a proper blade. It worked, but I was not machining it after, just cutting some angle iron for welding or something like that. I never did the opposite.

Reply to
homeowner

So how does all that relate to masonry disks - and what makes them good for masonry?

Reply to
Home Guy

It doesn't address the issue of cutting or grinding masonary. It just deals with what to use for cutting and grinding ferrous and non ferrous metals.

A partial answer is better than no answer at all.

Really, the way to decide what abrasive to use on a particular material doesn't have a straight forward answer. There are different grits in different sizes that break with different characteristics, and all of those factors affect cutting performance. Similarily there are different "bonds" which are the glues used to hold those abrasive particles together, and the bond the wheel uses makes a difference too.

So, deciding on the right disk to use in particular application is like deciding on what grease to use in a particular application; you generally need to get a recommendation from a company sales rep or tech support person that's been trained in that technology as a starting point, and then working with that expert to overcome any problems you encounter. But, when you have nothing else to go by, aluminum oxide, which is the abrasive best described as being "the most widely used general purpose abrasive" is the default choice.

'GRINDING WHEEL and ABRASIVES BASICS'

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Reply to
nestork

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