When assessing a jaw crusher, you must focus on the Feed Opening Size (mm), which determines the maximum stone size the machine can handle, and the Discharge Range (CSS), which dictates the final product size. High-performance units should feature high-manganese steel (Mn13Cr2 or Mn18Cr2) for jaw plates to ensure longevity. Additionally, verify the Eccentric Shaft material (typically 42CrMo) and the Processing Capacity (t/h) to ensure it meets your production requirements without overloading the motor.