# Grinding on the Side of the Wheel?



## Antman (May 9, 2010)

I have just received a gentle reminder to reread the SAFETY RULES. One that bypassed my conscious mind, I must have read it through my blind spot previously, is grinding on the side of the wheel.
  Remembering the furore I created when I asked about gloves, I shall try to be more circumspect.
   Why not?
    Ant


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## tmuir (May 9, 2010)

There are a couple of reasons not to grind on the side of the wheels.
First one it they are not even. What I mean by this is the front part of the wheel is trued up as part of the manufacturing process, they don't do this on the side which means there could be small bumps and ripples on the side that could ruin the finish of your part. 
But more importantly the wheels are not made to take side load so if you push too hard on the side of the grinding wheel it is possible to shatter them which could lead to a very nasty result.

Saying this I have been known to take very light cut on the side of the wheel but you must always keep in you mind if you load the side of the wheel too much you could find yourself in the back of an ambulance or worse....


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## rake60 (May 9, 2010)

In my early apprentice years I saw something that I hope to never see again.

A young man who was about my age at the time was grinding tools for an 
automatic screw machine. He decided to sharpen the edge of his newly made tool 
on the side of the grinding wheel. 

The wheel designated punching holes in the floor, ceiling and walls.
Ron was lucky to not been hurt in the incident.
He froze in place, not knowing what to do.

My worst memory of that event was our mentor who was 62 years old at that,
ran right through the path of debris flying off of that grinding wheel to shut the
grinder down. 

Standard grinding wheels are NOT designed for side loads!

Some grinding wheels are designed for side loads.

If you are not positive that the wheels on YOUR grinder are of that design.
*DON'T GRIND ON THE SIDES!*

*NO ONE* needs to lose an eye, both eyes, a hand or an arm in the pursuit 
of a hobby.

A misunderstood bench grinder can make you very dead, very quickly.

It seems like such a simple machine.

You can not allow yourself to be *"simpler"* than the machine.

Rick


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## johnthomp (Jul 2, 2010)

never a more true word said i saw the worst accident ever on a building sit roughly 8 years ago we were out in the sticks and atleast a 1 hour drive away from the nearest hospital or supply merchants a young lad must have been bout 20 at the time was useing a 9" angle grinder to gut an iron gurder after wearing his last carbon disc down to sod all the only ones leaft were for a 12" cutter so he came up with the genious idea of takeing the guard off the grinder so the larger disk would fit me watching this told my dad what was going on and word got round like the shits through a refugee camp and numerous lads on the site told him of the danger he was faceing but the 20 yr old know it all just took no notice 
  his last spoken words were its ok i do it all the time i just do it till its worn down enough to put the guard on as we all kept watching from a fair distance away he started the grinder and just touched the gurder with it and BOOOM ive never before that thought a fella could scream like that and dont particularly want to ever hear it again the isk had shattered into several lumps of shrapnel and hit him in the groin area blood was evrywhere no time for an ambulance he was in the back of a van with 3 first aid trained lads and off to the hospital i heared later that they got there just in time and the lad is permanently in a wheelchair haveing to **** and piss in bags for the rest of his life now 
   theres only one lesson i learned that day and that is 
    DONT REMOVE ANY GUARDS FROM ANYTHING THEY ARE THERE FOR A DAMN GOOD REASON


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## ieezitin (Jul 2, 2010)

Side grinding is a no no!.

Please all noobs here take note. When ever an oldtimer says dont do it please listen. Machines are like guns, it all depends on the pressure of the trigger pull, when the pressure is reached the lead flies.


Anthony.


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## Dirty_Vinylpusher (Jul 2, 2010)

A bit off topic but still about grinders...


Has anyone heard of/experienced a chemical reaction/fire/minor explosion when grinding both steel and aluminium on the same grinding wheel?

 ???


(Not as in grinding both materials at the same time, but one after the other.)


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## Maryak (Jul 2, 2010)

dvp,

IMHO generally speaking it's not a good idea to grind non ferrous materials on a grinding wheel, they clog the wheel, i.e. they remain stuck between the grit and the bonding material. When you then grind ferrous material the non ferrous left in the wheel gets very hot, expands and then BANG........ the wheel, (or bits thereof), at best will chase you round the shop; at worst- 
	

	
	
		
		

		
			






 If you do grind non ferrous then dressing the wheel before reverting to ferrous is a must.

It's a bit like filling up your car with petrol whilst smoking 99/100 OK, 1/100 POOF.

Best Regards
Bob


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## Cedge (Jul 3, 2010)

Saw a wheel explode once, when a know it all "fabricator" ignored a second warning to stop grinding on the side of the wheel of an old bench grinder. The guards were made of some kind of cast material and shattered when the wheel went "BANG" . It didn't kill the guy, but only because the guard absorbed a tremendous amount of the energy. 

A silver dollar sized chunk struck him center of the forehead and knocked him out cold. Everyone there thought he'd killed his dumbassed self. Without the guard, he'd have been dead as a hammer. He never needed the third warning and in fact refused to use a bench grinder the rest of his rather short time with our company. He was an accident waiting to happen and managed to create quite a spectacular display of pyrotechnics by cutting steel right over the gas/oxy lines of the cutting rig he was supposed to be so damned good with. 

I punched his final time card for him, after we had his clothing put out and knew he was not seriously injured. Near thing... though.

All guards on, edge of wheel only and, as Bob said.... no non-ferrous grinding. Those wheels are a bit fragile and more than a little touchy about being abused.

Steve


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## Lew_Merrick_PE (Jul 3, 2010)

Dirty_Vinylpusher  said:
			
		

> Has anyone heard of/experienced a chemical reaction/fire/minor explosion when grinding both steel and aluminium on the same grinding wheel?


While I have heard _tales_ of such incidents, I do not believe them. Iron filings properly rusted (turned into ferrous-oxide) mixed with aluminum powder (no, I am *not* going to give out ratios) makes Thermit. Yes, I have made Thermit. It is no toy and not for those not properly trained in handling it. However, it is highly unlikely that it ever formed spontaneously on a grinding wheel. The original inventor of Thermit was making an electrically conductive paint (such as that used on the Hindenburg) and its other "properties" were discovered by (tragic) accident.


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## tel (Jul 3, 2010)

> Iron filings properly rusted (turned into ferrous-oxide) mixed with aluminum powder (no, I am not going to give out ratios) makes Thermit.



Nope, it makes _*thermite*_. Worked with it years ago welding rail section together, interesting stuff and quite handy if you know what you are doing with it.


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## RobWilson (Jul 3, 2010)

tel  said:
			
		

> Nope, it makes _*thermite*_. Worked with it years ago welding rail section together, interesting stuff and quite handy if you know what you are doing with it.



Nope it makes *Thermit* ,,,,,,,Thermite is a generic term , ;D

Rob


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## tel (Jul 3, 2010)

Nah mate - thermite it is - you do _themit_ welding with _thermite_

http://en.wikipedia.org/wiki/Thermite

http://www.amazingrust.com/experiments/how_to/Thermite.html

http://www.chymist.com/Thermite%20reaction.pdf

http://www.weldprocedures.com/thermite.html

.... and there's another 5.8million hits on Google, if you care to look.

After that, Google 'thermit', you will probably be surprised at what you find.


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## johnthomp (Jul 3, 2010)

Dirty_Vinylpusher  said:
			
		

> A bit off topic but still about grinders...
> 
> 
> Has anyone heard of/experienced a chemical reaction/fire/minor explosion when grinding both steel and aluminium on the same grinding wheel?
> ...


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## RobWilson (Jul 3, 2010)

Well the the four old books i have that cover the subject all say the same thing,, Thermit ,,,,,mmmmmmmm they must be wrong if you and Google says so :

Photo from on of them 





Rob


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## bearcar1 (Jul 3, 2010)

Now this may seem a bit esoteric but as a small lad growing up in Grandpa's shop, I always saw my Dad as well as any of the other machinists, stand off to the side of the grinders when they would power them on. Later on, I was informed that the wheels had been known to fly apart during the spin up and by standing clear of the wheels arc, lessoned the chance of being struck by any shrapnel. Grandpa would remove the wheels on occasion and give them a light tap with a small brass hammer that he used for making gaskets. If the wheel would 'ring', that is resounded with a high tinny sound it was deemed OK and reattached to the motor's arbor. If the wheel sounded with a dull, 'flat' type of sound the wheel most likely had a crack in it and was broken up into bits with a sledge and discarded. As I grew older, this ritual became part of my assigned duties, along with keeping all of the machines well lubricated and clean and the floor swept. I still follow that regimen today and have indeed seen two wheels self destruct upon initial start up in all of my years. Safety first and live to tell all the stories, don't become one. DON"T grind on the sides of the wheels.

BC1
Jim


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## johnthomp (Jul 3, 2010)

how my thermite grinder happened it was a pile of rusty iron dust under the wheel that got covered with aluminium dust then more iron dust and was ignited by the sparks while i was sharpening a half inch chisel at 14 years old i wasnt to know and ive never used the side of a wheel at high speed but i guess its ok on a 180rpm wet stone 
  the thing that frightens me about grinding metals on wheels is the apparent chance of ending up with silicosis wich seems like a horrible thing to live with


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## Lew_Merrick_PE (Jul 3, 2010)

bearcar1  said:
			
		

> Now this may seem a bit esoteric but as a small lad growing up in Grandpa's shop, I always saw my Dad as well as any of the other machinists, stand off to the side of the grinders when they would power them on. Later on, I was informed that the wheels had been known to fly apart during the spin up and by standing clear of the wheels arc, lessoned the chance of being struck by any shrapnel. Grandpa would remove the wheels on occasion and give them a light tap with a small brass hammer that he used for making gaskets. If the wheel would 'ring', that is resounded with a high tinny sound it was deemed OK and reattached to the motor's arbor. If the wheel sounded with a dull, 'flat' type of sound the wheel most likely had a crack in it and was broken up into bits with a sledge and discarded. As I grew older, this ritual became part of my assigned duties, along with keeping all of the machines well lubricated and clean and the floor swept. I still follow that regimen today and have indeed seen two wheels self destruct upon initial start up in all of my years. Safety first and live to tell all the stories, don't become one. DON"T grind on the sides of the wheels.



Jim,

Good advice. I follow it myself and have seen several accidents related to wheel failure at start-up. One of the (now long gone) businesses we did work for in the shop I apprenticed in was Pacific Grinding Wheel. They used to hand out a chart about their grinding wheels (which included "side grind capable" wheels) along with safety information. Standing out of the radius of a wheel being started was rule #1 on their list.

Similarly, Everett (WA -- USA) was a timber town in those days. I have *seen* men killed when bandsaw blades broke and came screaming out along the radius of the saw. It only happens about 1 in 350,000 (OSHA figures from the mid-1970's) or so cases of a broken bandsaw blade, but it *does* happen. I have enforced a "no standing in the line of a bandsaw blade" rule in my shop as a result. My youngest (daughter) was taking "shop" in middle school. The shop teacher pooh-poohed her training. One of the students went to the hospital after getting a bandsaw blade through his foot that term. It is rare, but it does happen.

Things that spin *can* demonstrate the power of centrifugal acceleration. 3450 rpm (the usual pedestal grinder wheel speed) at 4 inches (the radius of an 8 inch wheel) is 82 mph (120 ft/sec). At e = mv²/2, it does not take much to turn that into a lot of ft-lb of energy. There are several places on the human body where 23 ft-lb is a fatal injury.


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## tel (Jul 4, 2010)

RobWilson  said:
			
		

> Well the the four old books i have that cover the subject all say the same thing,, Thermit ,,,,,mmmmmmmm they must be wrong if you and Google says so :
> 
> Photo from on of them
> 
> ...



Four books or no - 'therm_ite_' need the 'ite suffix to make any sense, do these book also refer to 'dynamit' or 'gelignit'? ;D

The clue is right there in the pic you posted 'Thermit' spelled with a capital 'T', denoting a trade name.

http://www.skwirk.com.au/p-c_s-4_u-107_t-285_c-953/naming-compounds/nsw/naming-compounds/introducing-chemistry/compounds-and-reactions


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## BenPeake (Jul 4, 2010)

Thanks for posting on this topic everyone. I've been grinding on the side of the wheel (sometimes with considerable force) ever since I've owned my grinder and to make things worse, I've always stood in front of the wheel when I've turned it on.

Because of this topic I'll never do either of these things again, so thanks for warning me about the dangers of grinding wheels.

Ben


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## tel (Jul 4, 2010)

Guess we've all, or most of us, been guilty of side grinding from time to time to get a particular job done, but it's not a good practice.


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## RobWilson (Jul 4, 2010)

??? Themit / Thermite use's iron (III) oxide,,,,,,,, ( Fe2O3 + 2Al &#8594; 2Fe + Al2O3 + heat) So it should use the suffix _ate_ for more/lots of oxygen ,,,,,,,,, Thermate ;D

Rob


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## tel (Jul 4, 2010)

;D Yeah, that makes sense. After all, we use ammonium nitr_ate_ to provide oxygen for a certain (ahem) 'procedure'. And potassium nitr_ate_ for another. Some'ow 'dynamate' doesn't sound quite right tho'.


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## RobWilson (Jul 4, 2010)

tel  said:
			
		

> ;D Yeah, that makes sense. After all, we use ammonium nitr_ate_ to provide oxygen for a certain (ahem) 'procedure'. And potassium nitr_ate_ for another. Some'ow 'dynamate' doesn't sound quite right tho'.


 Rof} Rof} Rof} Rof} Rof} 'dynamate' I think they sell that on QVC :big: :big: :big: :big:

Better get let this thread back on topic :hDe:

Rob ;D


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## steamer (Jul 4, 2010)

AHhh Lew beat me to it....ringing a wheel and standing to the side during the first minute is standard practice in the machine tool business...

With a 5 pound wheel, 8 inches in diameter, going at 3600 rpm, you have about 700 joules of kinetic energy.  Converting that to linear kinetic energy....as it's easier to "relate" to..

That's 5 pounds of razor sharp rocks flying at you at about 60 miles/hour

Now there's an image to think about.....

Dave


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## Woz (Jul 4, 2010)

I've been reading this thread with interest. Do the warnings about grinding on the side also apply to those drill sharpening jigs that work that way? 

Woz (in Oz)


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## steamer (Jul 4, 2010)

That's an interesting point....and I have not used one of those grinders....but if it's a "Standard" bench wheel...then I would have to say yes!....regardless of the fixture.

Lets face it....I know I have done it so I'll throw no stones most here have.....but in general you shouldn't for reasons already stated....


And for god's sake as well as your own..wear Glasses! 8)

Dave


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## steamer (Jul 4, 2010)

This might help...


[ame]http://www.youtube.com/watch?v=2pDL0ZQ-2Pk&NR=1[/ame]




Dave


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## Dan Rowe (Jul 4, 2010)

Dave,
I had to play the video because I have never heard a bad wheel. I think the videos are a bit of a ringer because he holds the wheel properly by the center hole in the first good test and for the second bad test he has what looks like the same wheel sitting on the bench which is not how to conduct the ringing test.

Dan


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## Lew_Merrick_PE (Jul 4, 2010)

Woz  said:
			
		

> I've been reading this thread with interest. Do the warnings about grinding on the side also apply to those drill sharpening jigs that work that way?



Woz,

The old General brand drill sharpening jig came with a warning to purchase a side-load grinding wheel for use with it. My own General drill grinding attachment was purchased in 1968, so I am bit out of date as to what warnings come with them today. When Pacific Grinding Wheel went out of business, I purchased a box of 72 side-load wheels from them. I assume, but do not know, that such wheels are still sold.


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## steamer (Jul 4, 2010)

Thanks for that info Lew. 

Dan, I'll take the second one down, as I don't want a staged one

Suffice it to say that if you don't get a distinct ring, you don't have a wheel

Dave


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## Dirty_Vinylpusher (Jul 5, 2010)

Yeah lots of good info here.

On that note I'm gonna scurry off and clean up all the dust around my grinder..... Thm:


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