I've been trying to figure out how to know when to discard a grinding
disc for an angle grinder. I've looked around on the internet, but
can't seem to find an answer to this. I know about the "use by"
date, but what's the best way to know when the disc is too worn and
should be discarded before it shatters?
I'm cheap. I replace them when it starts taking noticeably longer to
grind material away. Usually round 2/3 to 3/4 of the material from the
original edges to the swelled hub has been used. I've never had a
grinding disc or cutting disc "exploded". I've broken a few cutting
discs, and pieces flew off because I was over flexing it, but it didn't
"explode." It broke due to mishandling and abuse.
Only if you (1) know what you're missing and (2) have another disk.
The condition of their equipment drove me to bring my own, which after
all is what I needed to learn to use.
Schools here are funded mainly by local property taxes, and we
taxpayers debate, amend and vote on their budget at town meetings, so
they have an incentive to appear poverty-stricken.
Somehow they could find the big bucks to buy decent new equipment,
just not the small change for the supplies to support it. I had the
same problem as an Army communications repairman and a lab and shop
manager at a government research facility. Personal J.C.Whitney
mail-orders kept the Army Jeeps running, not necessarily with stock
Obviously, for the same RPM, the peripheral cutting speed declines as
the disk gets smaller.
You sort-of move the working angled edge-bevel towards the middle,
consuming the disk but also regenerating the cutting medium by
exposing new sharp particles.
BTW - for the disk to not wear at all is not a good thing, because it
becomes glazed. The particles at the surface become smooth and
polished and no longer cut. That can happen on large flat smooth
workpiece surfaces. Where the work has that sole characteristic, I
have a piece of scrap steel tacked to the edge of the trestle, so can
harshly dig the edge of the disk onto sharpish edges, to get new grit
That makes sense to me.
I'll just worry about inspecting the grinding discs for cracks or
other defects and replace them when damaged or the diameter gets
too small to work well.
Thanks for the explanation!