Danger comes from the fact that centrifugal force does not increase in direct proportion to an increase in speed, but chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s instead it increases as the square of that speed increase. When rotational speed doubles, centrifugal force quadruples. This effect means that relatively small changes in speed can produce significant increases in force. In the example mentioned, changing from 6,600 rpm to 7,700 rpm multiplies chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s the speed by 1.167. However, the corresponding centrifugal force would multiply by a factor of chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s 1.167 x 1.167, or 1.36. To take a more extreme example, consider the same wheel with a maximum safe operating speed chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s and chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s of 6,600 rpm run on a 5-inch right angle grinder at 10,000 rpm. This represents an over-speed of about 1.5 times the wheel''s designed speed. But the corresponding centrifugal force-and the corresponding rotational stress chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s on chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s the wheel-would be about 2.3 times chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s as much as the maximum allowed.

In short, never over-speed a grinding wheel. The chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s speed of the chicago-pneumatic1hp7inheavydutyverticalsandermodelcp865s grinder must be compared to the speed marked on the wheel or package to make sure the machine''s speed is at or below the maximum operating speed of the wheel. Surpassing this rating risks not just wheel breakage but also the safety of shop personnel. About the author: Roger Cloutier is a senior product safety engineer for the Norton Abrasives brand of Saint-Gobain Abrasives in Worcester, Massachusetts.

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