View Full Version : Die grinder as a cut off wheel
4x4mike
12-26-2008, 05:40 PM
I've had a couple of air powered 3" cut off wheels in my day but lately I've been using die grinders with an arbor for cut off wheels. Is this the same thing? The reason I ask is I've seemed to have toasted bearings in 2 die grinders that were used exclusively for cut off duty. One is a low grade IR and one is a Chicago Professional. Nether lasted all that long but before I buy another I want to make sure I'm getting the right thing.
I have a right angle die grinder (IR 301) that I like a lot. It's strong and doesn't use as much air as my other die grinders. I'd like to get a in line version that is similar and put the arbor for the 3" wheel on it. Should I do this or get the dedicated cut off tool? Is side loading the grinder killing the bearing?
44Runner
12-26-2008, 06:21 PM
I have an air die grinder and a specific cut off air tool that is very similar to the die grinder but much more robust. Seems to have more ass. Regardless I don't much care for using air for cutoff but do it on occasion. Make sure to lube your junk up and with al the air they go through make extra sure to have a inline separator...
darkstar
12-26-2008, 07:35 PM
cutoff wheels (or just about anything, really) are a pain in the ass on a cheap die grinder. Look for an industrial quality grinder (atlas-copco, cooper, dotco, dynabrade) with at least .5 HP. Be prepared to spend some $$$ if bying new, or look for deals on craigs or ebay..
My atlas-copco 12000 RPM die grinder will go through 1/4" plate as easily as my milwaukee 4.5" angle grinder with a cutoff wheel on it.
1TON73K5
12-26-2008, 11:00 PM
I bought a MasterPower Die grinder to use as a cut off gringer. Paid $180 for it on sale, Is as AWESOME grinder with great torque to really power thru sheet metal. I think it is like .9 HP rated. I have the MP4472 Master Power die grinder.
http://www.coopertools.com/catalog/pdffiles/SP-904_EN.pdf
darkstar
12-26-2008, 11:39 PM
cooper makes master power (as well as dotco). Very nice tools, I have one of those too. Not quite the balls that the atlas-copco has, but in a different league than automotive-grade die grinders like get from the tool truck, not to mention cheapies like harbor freight, etc.
4x4mike
12-28-2008, 06:10 PM
Cool, thanks for the advice. It looks like it's time to go shopping.
Die grinders are 20,000 rpm+. Most cutoff wheel blades are not rated anywhere near that. That is the reason to use a cutoff tool as a cutoff tool.
darkstar
12-28-2008, 07:17 PM
Die grinders are 20,000 rpm+. Most cutoff wheel blades are not rated anywhere near that. That is the reason to use a cutoff tool as a cutoff tool.
You make it seem as though all die grinders spin that fast. Most cheap ones do, but when you look at quality tools you can get them in a range of rotational speeds. Look for one that spins at 10-12000 RPM for using a cutoff wheel.
4x4mike
12-28-2008, 10:15 PM
Anyone have any experience with the IR 326 cutoff wheel? I was looking at the more commercial and ultra heavy duty models but I don't have the compressor to power any of them. I seemed to well with spinning cheap die grinders but not some of the ones mentioned.
jasonmt
12-28-2008, 11:33 PM
Die grinders are 20,000 rpm+. Most cutoff wheel blades are not rated anywhere near that. That is the reason to use a cutoff tool as a cutoff tool.
Most 3" cutting wheels are rated at 24,000+ rpm,
Most 3" cutting wheels are rated at 24,000+ rpm,
I just checked in my toolbox and the good wheels are rated at 24k. There are a lot of wheels that are not rated that high.
You make it seem as though all die grinders spin that fast. Most cheap ones do, but when you look at quality tools you can get them in a range of rotational speeds. Look for one that spins at 10-12000 RPM for using a cutoff wheel.
Why not just buy a cut-off tool? My Cornwell die grinder has adjustable speed settings but unloaded they all spin pretty fast. How fast? You don't know and neither do I.
darkstar
12-31-2008, 12:02 PM
Why not just buy a cut-off tool? My Cornwell die grinder has adjustable speed settings but unloaded they all spin pretty fast. How fast? You don't know and neither do I.
Not true. Good die grinders (and many that aren't that good, in fact) will have the rotational speed either stamped or printed on the body.
Wyoming9
01-01-2009, 02:32 AM
I can understand if you are cutting a lot of 1/4 inch plate why you would destroy them. :shaking:
I use cut off tools , That I have had for 20 plus years. They are larger than the die grinder.
I do use die grinders with 3 inch wire wheels and carbide cutters
Dry air and the right lubrication will work wonders for air tool life.
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