Grinding Wheel Safety: Respect The Maximum Speed | Modern
3/15/2003· For example, operating a reinforced, 9-inch diameter, Type 27 wheel rated for a maximum speed of 6,600 rpm on a 7-inch angle grinder with a speed of 7,700 rpm can cause the wheel to crack. This cracking can lead to breakage later. The following actions—all of which are not recommended—can also lead to an over-speed condition: