pic: Angle Grinder Carnage

Just a friendly reminder that shop accidents happen. If it weren’t for the guard on the grinder and a pair of safety goggles, an injury would definitely have occurred. This grinder showed no signs of fatigue. Safety problems will arise where you least anticipate them, so please always be safe!

Its always been my rule to have a full face shield on when using any type of grinder/sander/cutoff saw. Not to stop sparks and the like but because those things blow up and when they do they don’t show it sometimes and could really hurt some one.

I could be wrong, (please somebody correct me if I am) but I am pretty sure you are not supposed to grind aluminum with that type of abrasive disc. Grinding aluminum can gum those up and cause them to explode like that because it gets in the pores of the disc and causes it to expand. Then again, somebody please correct me if I am wrong.

I once burned a hole through one of my shirts by leaning too close to the sparks. Good times.

You’re not wrong.

I learned of this phenomenon on regular bench grinder and surface grinders, but I’ve (thankfully) never seen it happen. I heard that the aluminum gums it up, causing it to just rub and not cut, heat up, and explode.
In any case you might want to invest in a decent bandsaw for aluminum cutting. Easy and versatile.

Speaking from experience - ALWAYS anticipate failures from angle grinders/cutters like this one. They happen routinely, and can be caused by the *slightest *amount of mis-use.

What was this cutter being used to cut? How experienced was the operator? What type of blade was it?

This is correct, at least in principle. Abrasive wheels are generally not designed for aluminum (I’ve never seen one anyway!) and should not be used to cut aluminum for a variety of reasons. Cutting discs should only be used to cut the materials they’re rated for.

I don’t think it’s because aluminum ‘gets into the pores’ of the cutting wheels. I believe its because aluminum adheres to the disc, preventing the disc from cutting properly and causing catastrophic heat build-up in the disc from friction.

This. This. This.

Even with the blade guard they can still cause a lot of damage. A friend of mine wound up needed 40 stitches when a blade like this shattered and tore into his face. He was wearing safety glasses, so he can still use his eyes, but it still really messed him up.

While you are right, this doesn’t look like a fiber based grinding wheel. To me it looks like a stamped metal wheel with some kind of coating such as carbide or diamond. Similar to this.

Safety FIRST!
I am apart of my teams manufacturing team and I do have to say that being safe while working with robots is something we take a lot of time to enforce. Always be prapared for anything catastrophic to happen because sometimes it could be life threatening! Safety SHOUT OUT FROM 195!!!

We had an incident where we were clamping some metal to a saw and the clamp ended up punching a hole in the saw. Ironically, it’s now easier to clamp. It’s a very nice clean hole, had you not been there you would think it was made like that.

You have a few choices grinding Aluminum. We use a bench sander & sanding disks on our angle grinder rather than grinding. Flapper wheels work also.

1(Probably best ) use wheels rated for Aluminum.
2 Use lots of lubricant like WD-40. Never done this. I am told that it is messy.
3 Don’t let the wheel load up. Which will require frequent redressing. Not the best of ideas.