i had a 4 inch cut off wheel break while I was trimming the inner fender well for header clearances on my old duster, I got lucky as I got only one bad cut on one finger from the debris I was using a Chicago air small (4 inch diameter) cut of tool with 21,000 to 23,000 RPM, Harbor freight cut off wheels
My message is be safe, don't push the tool beyond its safe operating designs