"Things You Wouldn't Know If We Didn't Blog Intermittently."
The discs are fibrous and not solid metal. I've never had one explode, but I can easily see it happening. I think I'll be buying a full face shield and wearing heavier clothing next time I use one.
Text amended; thanks for the heads-up Larry.
7200 [RPM] / 60 [s/minute] * circumference 0.33 m = 40 m/s, or ~ 90 mph hm still not nearly as fast as grenade shrapnel or a bullet.