Ingersoll Rand 84 CFM ” Wheel Vertical Grinder has a , double-row ball bearings for a smooth operation. 3. 0 Durable solid steel motor and arbor housing vertical grinder with a free speed of 6000 has an air inlet size of 1/2″ and a minimum sized hose size of 3/4″. Vertical grinder features a patented motor controller for increased productivity while enhancing operator safety. It has an adjustable side handles, an ergonomic main handle and self-locking throttle to reduce operator fatigue. It has a built-in mist lubricator that automatically oils the motor when throttle is activated and has an integral steel guard for extra strength as well as protection.