Crusher Operation What is the Closed Side Setting (CSS)?-Minimum gap setting of when the mantle bowl rotates within the crusher or moving plate is closest to the fixed plate in a jaw crusher (‘closed’ position) - Gyratory’s: typically 90 to 220mm-Secondary’s: typically 30-60mm-Tertiary’s/Scats: typically 8-20mm-Jaw Crushers: 80-150mm