Sandvik CH440 Piston Wearing Plate | 442.8730-01 Step Washer

Technical Specifications: Sandvik CH440 Piston Wearing Plate

The Piston Wearing Plate (442.8730-01) is the critical axial bearing at the heart of the Sandvik CH440 Hydroset system.
As specialized crusher part suppliers, we understand that this single component supports the entire weight of the moving assembly (Mainshaft + Mantle) plus the dynamic crushing force.
Our replacements are engineered from premium Leaded Bronze to prevent catastrophic seizing of the Hydroset cylinder.

Core Advantages: Metallurgy & Precision Lapping

The failure of a Step Washer usually means the destruction of the Mainshaft.
Our Spare parts manufacturing process prioritizes tribology (friction science):

• High-Leaded Bronze (C93700): We utilize an alloy with 20-22% Lead content.
  Under extreme axial loads, the lead creates a microscopic self-lubricating film.
  This provides a “fail-safe” mechanism during startup or shut-down when hydrostatic oil pressure is low.
• Centrifugal Casting: Gravity casting cannot achieve the density required for a 38kg thrust bearing.
  Our plates are centrifugally cast to eliminate porosity, ensuring the plate can withstand compressive loads exceeding 150 MPa without deforming.
• Precision Lapping: After CNC machining, every plate undergoes a flat lapping process.
  This achieves a flatness tolerance of <0.02mm, which is essential for maintaining the high-pressure oil wedge that separates the plate from the steel piston.

Performance Comparison: Why Flatness Matters

In a Hydrocone crusher, the “Wearing Plate” must float on oil.
See why our precision Crusher spares outperform standard cast parts:

Field Diagnosis: Inspecting the Hydroset Bearing

When the mainshaft is removed, inspecting the 442.8730-01 plate is mandatory.
Look for these signs:

• Edge Loading (Polished on one side): If one side of the plate is mirror-polished and worn thin while the other is dull, the Mainshaft is bent