Jaw plates are major wear parts in a jaw crusher. Their life depends on the ore, chamber profile, material, feeding and maintenance. The following five measures help assess wear causes and improve operation; results depend on the installation.
1. Select the Alloy for the Ore
Select jaw plate material for ore abrasiveness, impact loads and tooth profile. Grades such as Mn18Cr2 and Mn22Cr2 require assessment against the drawing standard, heat treatment and operating trials. Alloy additions do not guarantee longer life.
| Feed Material | Assessment Parameters | Material Selection | Validation |
|---|---|---|---|
| Limestone and Coal | Size, strength and contaminants | Assess impact and work hardening | Record wear and tonnes processed |
| Copper and Gold Ores | Mineralogy and abrasiveness | Select alloy for actual conditions | Use comparable operating trials |
| Granite, Basalt and Quartzite | Abrasiveness, lump size and impact | Balance profile, toughness and wear resistance | Compare cost per tonne |
| Magnetite and Hematite | Gangue, gradation and hardness | Do not assign an alloy by ore name alone | Record cracks and wear distribution |
Application Assessment: Before changing material, record the current grade, tonnes processed, wear pattern, damage and operating conditions. Use comparable operating trials and compare actual cost per tonne, including purchase, downtime, installation and inspection costs.
2. Optimize the Closed Side Setting (CSS)
CSS directly affects capacity and wear patterns. An excessively tight setting can cause:
- Excessive jaw plate loading
- Accelerated localized jaw plate wear
- Increased power demand
- Increased risk of jaw plate fracture
CSS Selection for Different Applications:
| Application | CSS Selection | Assessment Focus |
|---|---|---|
| Primary Crushing of Blasted Ore | Set for the model and product target | Feed, power and wear distribution |
| Secondary Crushing | Stay within model limits | Reduction ratio and downstream capacity |
| Construction Waste Recycling | Assess material and contaminants | Blockage prevention, tramp metal removal and product size |
Practical Guidance: Record wear distribution, CSS, feed and power during scheduled inspections. Check model limits before adjustments; localized wear alone does not justify widening CSS or increasing material hardness.
3. Control Feed Size, Distribution and Rate
Uneven feeding, oversized lumps and unsuitable feed gradation affect wear. Check the following against the equipment manual:
- Maximum Feed Size: Control lump size against the permitted feed size for the specific crushing chamber; distinguish feed opening dimensions from maximum feed size.
- Feed Distribution: Use a suitable feeder to distribute material evenly across the chamber width and avoid uneven loading.
- Feed Rate: Maintain steady feed within permitted chamber level, power and throughput limits; avoid bridging, uneven loading and overload.
- Pre-screening Fines: Assess pre-screening from feed gradation, moisture, clay and downstream requirements; no single aperture suits all installations.
Application Assessment: When assessing pre-screening, compare bypass proportion, crusher load, product gradation, screen maintenance and total cost per tonne.
4. Inspect and Rotate Plates as Specified
Inspect jaw plates according to the maintenance schedule and adjust inspection frequency to the wear trend:
- Check for cracks, particularly around bolt holes and lower edges
- Record remaining thickness and tooth profile at consistent points to compare wear along the plate.
- Rotate only jaw plates designed for rotation, following the model-specific maintenance procedure.
- Replace plates in accordance with maintenance requirements when wear limits are reached, cracks appear or secure fastening cannot be maintained.
Plate Rotation Plan:
| Condition | Action | Check |
|---|---|---|
| Rotatable One-piece Jaw Plate | Rotate to the model manual | Profile, seating and fastening |
| Segmented Jaw Plates | Reposition segments to the manual | Maintain correct fixed and movable positions |
| Wear Limit Reached or Damage Found | Replace to the maintenance procedure | Cracks, remaining thickness and fit |
5. Install Correctly and Apply Specified Fastener Torque
Correct installation helps prevent loosening, seat damage and premature failure:
- Thoroughly clean wedge seats before installation
- Apply the manual torque or tensioning procedure for the specific model, bolt specification and lubrication condition.
- Recheck fastening at the intervals and using the procedure specified in the equipment manual.
- Check plate movement, fasteners and seating condition during scheduled inspections.
- Follow the OEM procedure for one-piece or segmented jaw plate replacement; do not interchange fixed and movable plates unless permitted by the design.
Maintenance Reference Checklist
| Method | Implementation | Recorded Metric | Assessment Basis |
|---|---|---|---|
| Material and Profile Selection | Trial against conditions and drawings | Cost per tonne | Comparable operation |
| Optimize CSS | Stay within model limits | Power and product gradation | Production records |
| Assess Pre-screening | Account for fines and clay | Crusher load and bypass quantity | System operating cost |
| Follow a Rotation Plan | Only for rotatable designs | Wear position and profile | Model maintenance manual |
| Standardize Installation | Fasten and inspect as specified | Movement, cracks and seating | Installation acceptance records |
Assess materials, feeding, CSS and maintenance together using cost per tonne and downtime losses, assessing improvement from comparable operating records.
Need Jaw Plates Matched to Your Drawings?
Send the full model, drawing number, tooth profile, mounting dimensions and current material for installations such as Metso C Series or Sandvik CJ Series. Assess Mn13Cr2, Mn18Cr2, Mn22Cr2 and other material options against drawing-based manufacturing requirements. Request a Quote