Overview
The main shaft nut (spindle lock nut) is a heavy-duty alloy steel fastener that threads onto the top of the main shaft in a Symons cone crusher. It clamps and secures the cone head and mantle assembly to the shaft, maintaining the proper preload that prevents loosening under the continuous vibration and impact loads of crushing operation.
Our main shaft nuts are forged from 42CrMo or 40Cr alloy steel , with the trapezoidal thread and clamping face CNC-machined to precise tolerances. Quenching and tempering heat treatment achieves high tensile strength and toughness, ensuring the nut maintains clamping force without cracking or stripping under severe service conditions.
Quality & Application
Each main shaft nut passes comprehensive inspection including thread profile verification, hardness testing and dimension check before shipment. Anti-rust coating is applied for protection during storage and transit.
Standard main shaft nuts are stocked for all common Symons spring cone crusher sizes. Custom thread diameters, pitches and hex sizes are available for non-standard crusher configurations. As a critical fastening component, a properly manufactured main shaft nut is essential for secure mantle retention, safe crusher operation and prevention of catastrophic assembly failure in mining and quarry operations.
Key Features
- Forged Alloy Steel: 42CrMo alloy steel forging provides high tensile strength and resistance to loosening under vibration.
- Precision Thread: CNC-machined trapezoidal thread ensures proper engagement and consistent clamping force.
- Vibration Resistant: Heat-treated material and proper preload prevent self-loosening under continuous crusher vibration.
- Secures Critical Assembly: Maintains proper mantle preload and cone head position for consistent crushing performance.
- OEM Interchangeable: Fully interchangeable with original Symons cone crusher main shaft nut dimensions and thread.
- Custom Thread Sizes: Custom thread diameter, pitch and hex size to match your specific crusher model.
Compatible Machines
Fits Symons Cone Crusher (2ft / 3ft / 4.25ft); Symons Cone Crusher (5.5ft / 7ft); Spring Cone Crushers (Custom Fit Available).
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