Themac tool post grinders range in size from 1/4 to 1 HP. In the past, we have even offered 3 HP grinders but have since discontinued them. The material to be ground, metal removal rate, the wheel used, and operation to be performed will determine the power requirements for a specific grinding operation. Because so many factors are involved, there is no easy and accurate calculation to determine the horsepower requirements for a grinder.
However, the following table* can be used as a quick reference guide. A good rule of thumb to use is ten horsepower for every cubic inch of material removed per minute.
Ferrous Stock Removal
(Rate vs. Horsepower)