Discharge particle size adjustment range of jaw crusher

Discharge particle size adjustment range of jaw crusher

Jaw crusher’s discharge size is controlled by the closed side setting (CSS), which refers to the minimum gap between the movable jaw plate and fixed jaw plate at the bottom of crushing chamber. Different jaw crusher models have distinct adjustment ranges.

Typical Adjustment Range

  1. Small mini jaw crusher (PE 150×250, PE 200×300) Adjustment range: 10 – 40 mm Suitable for laboratory, small waste concrete, quartz stone sample crushing.
  2. Medium jaw crusher (PE 400×600, PE 500×750) Adjustment range: 20 – 60 mm Widely used in gravel aggregate, mine coarse crushing line.
  3. Large primary jaw crusher (PE 600×900, PE 750×1060) Adjustment range: 30 – 100 mm For hard rock quarry, large-scale raw ore primary crushing.
  4. Mobile jaw crushing plant Same CSS range as corresponding stationary jaw models, convenient on-site adjustment.

Adjustment Principle

The discharge gap is changed by adjusting the thickness of toggle plate shims at the back of the crusher. Adding shims widens the discharge opening to get coarser output; removing shims reduces the gap for finer products.

Important note:

  • The actual output particle size distribution is wider than the CSS setting. The maximum discharged particle is roughly 1.5~2 times the closed side setting.
  • Harder rock, wet sticky material will affect the final gradation even if the gap remains unchanged.
  • Never adjust the gap under full load or while the machine is running.

Main Influencing Factors of Discharge Size

  • Toggle plate and jaw plate wear: worn liners will increase actual discharge size
  • Feed material hardness and moisture
  • Feed blockage inside crushing chamber
  • Rotation speed of eccentric shaft