## TECHNICAL NOTES 5 CRUSHERS

Jaw crushers are operated to produce a size reduction ratio between 4:1 and 9:1. Gyratory crushers can produce size reduction ratios over a somewhat larger range of 3:1 to 10:1. The primary operating variable available on a crusher is the set and on jaw and gyratory the open-side set (OSS) is specified. This reflects the fact that