Rock Crushing Rule of Thumb - 911 MetallurgistDec 16, 2015 . Above 725 tonnes/hour, jaw crushers cannot compete with gyratory . The desired grizzly opening for an underground jaw crusher is equal to.grizzly gyratory crusher,Gyratory Crusher Applications - Breaker TechnologyThe gyratory crusher is located at the bottom of the rock box. Material is . The size of your crusher or grizzly also affects the selection size of breaker. Hydraulic.