Metso HP Series Head Ball | 70-2495-0500 Crusher Spares

Technical Specifications: HP Series Head Ball (70-2495-0500)

The Head Ball (70-2495-0500) is a critical structural component in the HP Series cone crusher, acting as the pivot point for the main shaft assembly. As premier crusher part suppliers, we understand that this component must withstand immense compressive loads while maintaining a low-friction interface with the Socket Liner. Unlike cast replicas, our Head Balls are manufactured from high-strength forged steel to ensure zero structural failure.

Core Advantages: Manufacturing & Precision

The performance of the Head Ball directly impacts the lifespan of your Bronze Socket Liner. Our manufacturing process for these Spare parts ensures optimal tribology:

• Forged Integrity: We utilize Forged Alloy Steel (42CrMo4) rather than casting. Forging aligns the grain flow of the steel to the spherical shape, increasing fatigue strength by over 40% compared to cast alternatives.
• Induction Hardening: Only the spherical surface acts as a bearing. We apply precise induction hardening to reach 55-60 HRC on the surface for wear resistance, while keeping the core tough (approx. 280 HB) to absorb crushing shocks without shattering.
• Mirror Finish Grinding: After hardening, the sphere is CNC ground and polished to a surface roughness of Ra 0.4. This “mirror finish” is critical to maintaining the oil film wedge that protects the bronze socket liner from scoring.

Performance Comparison: Surface Finish Matters

Using a substandard Head Ball is the fastest way to destroy a new Socket Liner. Here is why our precision parts matter:

Field Diagnosis: Inspecting Your Head Ball

Unlike Wear parts like the mantle, the Head Ball does not need changing every liner change. However, you must inspect it closely when the head is removed:

• “Stepping” or Ridge Formation: Run your fingernail across the spherical surface. If you feel a distinct ridge or step where the socket liner contact area ends, the ball has lost its sphericity and must be re-machined or replaced.
• Blue/Black Discoloration: This indicates extreme overheating (“Burned”). The oil film failed, and metal-to-metal contact occurred. The surface hardness is likely compromised (annealed), and the part is scrap.
• Pitting: Small pits on the surface will act as cheese graters against the soft bronze socket liner. Do not reuse a pitted head ball.

Expert Tip: Installation & Sealing

The “interference” Factor: The Head Ball is typically interference-fitted (shrink fit) onto the Main Shaft.

Critical Step: When installing P/N 70-2495-0500, ensure the Main Shaft seat is perfectly clean. Heat the Head Ball in an oil bath to approx. 150°C (do not exceed 200°C to avoid tempering the surface) to expand it before sliding it onto the shaft.

Pro Tip: Always replace the Wiper Ring or seal that protects the spherical surface. Contamination in the socket oil is the #1 killer of this component.

Frequently Asked Questions (FAQ)

Q1: Why is this part not made of Manganese Steel like the liners?
A1: Manganese steel (Mn18) is designed to work-harden under impact but has a rough surface and poor dimensional stability. The Head Ball requires a precision, low-friction bearing surface to glide against bronze. Alloy Steel (42CrMo4) is the only suitable material.

Q2: Can I re-use my old Head Ball with a new Socket Liner?
A2: Yes, providing it passes inspection. Measure the sphericity with a template or CMM. If the deviation is less than 0.05mm and the surface is polished without scratches, it can be reused. If in doubt, replace it to protect the expensive new bronze liner.

Q3: Does this part fit all HP models?
A3: The P/N 70-2495-0500 is specific to certain configurations within the HP range. While the design concept is identical across the series, the dimensions vary. Please confirm your machine’s serial number with our crusher part suppliers team to ensure compatibility.

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