Tool Angle grinders. Most dangerous tool in the shop?

Here is my video on angle grinders. Is it the most dangerous tool? This isn’t advice - just my observations. Use your own sense please and take care of yourself. What else should you be on the lookout for?

 

[Janger]

I wonder if the makita grinder is defective and should stop faster than it does. I tried to find examples of it being used - couldn't find much. Anybody else got one? GA5020?

 

[6.5 Fan]

I had a large 6 or 7 inch Makita years ago, sold it due to violent start up kick and being to damn big and heavy. I think it took a long time to come to a stop.

 

[Hacker]

My 7" Makita is a beast and with a flapper disc takes 8 seconds to stop. The Makita 5" with a new grinding disc takes 7 seconds.

 

[Dan Dubeau]

I have an old 5" makita rat tail and it takes forever to spin down. I prefer my makita 4.5" cordless for most projects as it has a brake, and the handle shape fits my hand better. I find normal 4.5" barrel grinders hard to hold with my not so functional right now right arm and reduced grip strength, and prefer thinner handles.

The 5" makita is a great grinder for bigger projects though. It's probably 25 years old and still going strong.

 

[Gearhead88]

I know guys that have had grinder incidents with injuries however I don't have any grinder carnage stories to share but I have set my coveralls on fire a time or two , I've never been much of a dancer , unless I'm on fire.

 

[Hacker]

Setting your coveralls on fire does get your attention, but cutting into the finger on an insulated welding glove with a plasma cutter takes it to the next level.

 

[6.5 Fan]

Hmmm, the best dancer i ever saw was my dad, he was oxy/act cutting on a snow plow. was wearing the old style of winter boots with a sipper on the front which wasn't done up. A molten chunk of slag fell in the open boot, the result was hilarious.

 

[Brent H]

Remember that your grinder needs time to slow down- it cannot instantly stop or centrifugal force will loosen the blade and that is not a good thing. Right now I want to chuck my dewalt cordless drill into the bin because it instantly stops. After a few reps of this - especially with a larger bit, the chuck is lose. Totally because somebody thought it was a good idea to use it for screws and drilling - stupid dewalt people - argh

Metabo used to have a fast release collet on their grinders wait for it slow and engage the brake. The stop caused the nut to loosen and you could pop off the blade without tools. The bigger the disk the faster it worked.

 

[SomeGuy]

Remember that your grinder needs time to slow down- it cannot instantly stop or centrifugal force will loosen the blade and that is not a good thing. Right now I want to chuck my dewalt cordless drill into the bin because it instantly stops. After a few reps of this - especially with a larger bit, the chuck is lose. Totally because somebody thought it was a good idea to use it for screws and drilling - stupid dewalt people - argh

Metabo used to have a fast release collet on their grinders wait for it slow and engage the brake. The stop caused the nut to loosen and you could pop off the blade without tools. The bigger the disk the faster it worked.

I've never had that problem with the brakes on my Dewalt drills unless my hand starts touching the chuck while spinning. Even then, the speed and safety gained from not having to wait for things to spin down is worth a bit of inconvenience.

 

[Brent H]

@SomeGuy - really? You must have got a good one. Dewalt has the crappiest quick change drill chucks going IMO - mine (on the drills not drivers ) all failed at work and spun bits - my one at home stops - bang dead - chuck gets loose all the time unless you super tighten it. We have even pipe wrenched the chuck for work where a failure is not good. I have shot drills out of it at times or they get fouled up or drop out after drilling- or during drilling - really dangerous with a hole saw going sideways. My next is to go back to keyed chuck and corded drills for hole making.

 

[SomeGuy]

@SomeGuy - really? You must have got a good one. Dewalt has the crappiest quick change drill chucks going IMO - mine (on the drills not drivers ) all failed at work and spun bits - my one at home stops - bang dead - chuck gets loose all the time unless you super tighten it. We have even pipe wrenched the chuck for work where a failure is not good. I have shot drills out of it at times or they get fouled up or drop out after drilling- or during drilling - really dangerous with a hole saw going sideways. My next is to go back to keyed chuck and corded drills for hole making.

Which one do you have? I have a few different of the cordless ones all with the keyless ratcheting, no real issues to speak of.

 

[historicalarms]

I have 3 Dewalt 1/2 drills with keyless chucks, one is home hardware purchase with plastic chuck and is as Brent describes, will loosen off but the other two are industrial models made of steel and I cant ever remember either of them loosening on their own. The only reason I have the home hardware one is that they all take the same batteries & I could buy the entire new outfit with 2 batteries for less than the batteries alone.

 

[Janger]

Remember that your grinder needs time to slow down- it cannot instantly stop or centrifugal force will loosen the blade and that is not a good thing. Right now I want to chuck my dewalt cordless drill into the bin because it instantly stops. After a few reps of this - especially with a larger bit, the chuck is lose. Totally because somebody thought it was a good idea to use it for screws and drilling - stupid dewalt people - argh

Metabo used to have a fast release collet on their grinders wait for it slow and engage the brake. The stop caused the nut to loosen and you could pop off the blade without tools. The bigger the disk the faster it worked.

Ok that’s an interesting theory - but - counter example coming up - what about the mitre saws with brakes that stop the blade very quick. Also above some grinders stop faster the dewalt cordless. Hmmm

 

[DPittman]

Ok that’s an interesting theory - but - counter example coming up - what about the mitre saws with brakes that stop the blade very quick. Also above some grinders stop faster the dewalt cordless. Hmmm

My mitre saw has a left hand thread that keeps that from happening.

 

[Brent H]

If I could post a video I would give it a go -
Maybe will try - on my lathe and drill press keyless chucks they tighten as load is applied. Not so sure about the the dewalt?

I rarely ever use the 2 pin lever on any grinder and will just tighten that by hand.

 

[Janger]

My mitre saw has a left hand thread that keeps that from happening.

So if grinders had a left hand thread the brake could stop it faster?

 

[Susquatch]

Ok, so now you guys got my attention. I'll have to look at all my rotary tools to see what has what.

What I can say is that I've never had a problem like any of you describe. But there is always a first time. And I would not want to get hurt needlessly.

The biggest problem I've seen is a grinding wheel blowup on an angle grinder. It has never happened to me, but I prolly know a half dozen farmers that looked like they pulled the pin on a hand grenade. One guy lost an eye and another lost a few fingers. All very nasty injuries. All of them putting side pressure on a wheel that wasn't designed for that.

 

[trlvn]

The biggest problem I've seen is a grinding wheel blowup on an angle grinder. It has never happened to me, but I prolly know a half dozen farmers that looked like they pulled the pin on a hand grenade. One guy lost an eye and another lost a few fingers. All very nasty injuries. All of them putting side pressure on a wheel that wasn't designed for that.

If you think about it, it is a lot like driving down a gravel road at 80 kpm and jumping off the vehicle. Landing face first. Thinking of a grinding wheel as a potential grenade is a pretty good analogy.

Craig

 

[SomeGuy]

If you think about it, it is a lot like driving down a gravel road at 80 kpm and jumping off the vehicle. Landing face first. Thinking of a grinding wheel as a potential grenade is a pretty good analogy.

Craig

Which is why, regardless of the extra cost (which isn't much for the home gamer), I use flap wheels instead of grinding discs. They're so much less likely to explode.

 

[Darren]

The biggest problem I've seen is a grinding wheel blowup on an angle grinder. It has never happened to me, but I prolly know a half dozen farmers that looked like they pulled the pin on a hand grenade. One guy lost an eye and another lost a few fingers. All very nasty injuries. All of them putting side pressure on a wheel that wasn't designed for that.

Had a zip disk come apart on me about 20 years ago. Tore up my finger a bit. About 5 years later a small chunk of the disk popped out of my finger. I can still feel something in there. I've been a bit more careful since...