Grinding wheel wear limits

[Kscardsfan]

I'm sure this has been asked and answered a hundred times on here, but I can't find anything. Is there a published spec on when 4.5" and 7/9" angle grinder wheels have hit their useful lifespan? Some kind of maximum allowable edge loss etc? A quick google search this afternoon left me more questions than answers. So naturally I’m turning to you guys.

 

[The Cobbler]

something I never thought of. There's a you tube guy that uses his worn down grinder wheels on a hand held air grinder for getting into tight spaces when doing body work .
interested in watching this thread

 

[Kscardsfan]

something I never thought of. There's a you tube guy that uses his worn down grinder wheels on a hand held air grinder for getting into tight spaces when doing body work .
interested in watching this thread

I’ve had a cut off wheel blow up on me and the grinder wrap itself up into my pants and shirt before. And I see guys using what I assumed to be 4.5” wheels with a whole lot of open air between the guard and the edge of the wheel, which seems to be a perfect opportunity to pull something into the machine and get it thrown around with you still attached to it in my way of viewing the world. So I’m sure there are limits to how far you can use one safely. But I just can’t find them anywhere.

 

[seber]

The smaller the wheel becomes, the slower the perifery is running. Other than guard issues, it just gets safer as it gets smaller.

 

[mike93lx]

On an angle grinder, it is trash when it no longer can do the work from being too small or it is damaged

 

[American Locomotive]

I typically burn cutting discs down to the grinder hub (if I'm cutting sheet metal), and I burn grinding discs down to the point where more wheel dust than metal sparks come off.

The discs are homogenous throughout and don't lose integrity as they wear down.

The resins do however age, and most grinding and cutting discs do have an expiration date stamped on the hub somewhere.

 

[mike93lx]

I typically burn cutting discs down to the grinder hub (if I'm cutting sheet metal), and I burn grinding discs down to the point where more wheel dust than metal sparks come off.

The discs are homogenous throughout and don't lose integrity as they wear down.

The resins do however age, and most grinding and cutting discs do have an expiration date stamped on the hub somewhere.

Organic abrasives (what grinding discs are made of) are also extremely moisture sensitive.

I used to work for a huge abrasives company and we had to air condition the plants that made organics.

 

[2oolhound]

The resins do however age, and most grinding and cutting discs do have an expiration date stamped on the hub somewhere.

The expiry date (because of the bonding agent used to carry the abrasive) is supposed to be printed on the very inside around the mounting hole.

 

[dwasifar]

So I guess the grinding discs that came with my angle grinder have been expired since April 2019:



I didn't know about expiration dates, so the five of these that came with the grinder have just been sitting around collecting dust until I got around to grabbing one. That top one was new a couple of weeks ago. And now I learn I was taking my life in my hands!

I guess I have to go find a thread about best grinding discs now, because I don't think these are it.

 

[dutchgray]

^ I would run those and not even worry about it, with the guard fitted, as long as they had been well stored.
The 4 1/2" are pretty tame compared to the bigger stuff when it goes wrong, but I have never had a 4 1/2" grinding disc blow up and have run wheels that were so old they didn't have expiry dates on them.

But grinding discs are cheap so if you're worried, just bin them.

 

[oldwino]

Never had an issue with well worn wheels. They are good until they don’t have the reach left to do what you need.

 

[carbleaks]

I use the 4.5 cutoff wheels until they are about halfway worn down. I then keep them for when I need to get into tight areas. Once they are that small they don't last very long though.

 

[tarbellb]

You can gain some extra cutting time by

dunking them in water for a couple ours - THEY GROW

 

[2ndGearRubber]

The smaller the wheel becomes, the slower the perifery is running. Other than guard issues, it just gets safer as it gets smaller.

I personally run until I can notice performance loss due to the slower edge speed. Makes a big difference in pace.


Like everybody else, I have a collection of never used but "just in case" mostly worn down wheels.