I've used many over the years and had a few explode in my younger days.
Like Denny said, keep body parts and other people out of the line of fire.
Don't push them hard and don't get them in a bind.
Also check the RPM rating on the wheel with the RPM of the grinder. A lot of stem grinders have high RPM's.
If I can't find the RPM rating on the wheel, it goes in the trash.
Edit: another tip is if they start vibrating, stop and check it. Then trash it, because it's getting ready to let loose.

Don

Last edited by 2-Ton; 09/07/2015 3:21 PM.
1967 GMC 9500 Fire Ladder Truck
"The Flag Pole"
In the Stovebolt Gallery
1946 2-Ton grain truck
1946 3/4-ton pickup,
1953 1-ton pickup
1957 1-ton flatbed dually,
1954 Pontiac Straight Eight
Of all the things I've lost in my life, I miss my mind the most!