The Dual Challenge in Sealing Bore Machining
In the field of precision machining, bores used for sealing applications frequently face a "dual challenge." Manufacturers must ensure strict dimensional accuracy while simultaneously keeping the surface roughness stable within a very specific range—it cannot be too smooth, nor can it be too rough.
Take the hydraulic cylinder-piston sleeve in engineering machinery as a prime example. Because the piston requires continuous lubrication as it moves, the cylinder bore wall must maintain a certain degree of roughness to form a reticulated pattern (cross-hatch). This texture is essential for acting as a reservoir to store lubricating oil, preventing dry friction and premature wear.
The Customer's Dilemma: Forged Aluminum Hydraulic Cylinders
A client recently undertook a new project to manufacture forged aluminum hydraulic cylinders and approached us with stringent requirements:
• Dimensional Accuracy: Must meet IT7 grade.
• Surface Roughness: Must be strictly controlled between Rz 2 – 6 μm.
• Surface Texture: Must form a uniform reticulated pattern with a 0.1 mm pitch.
Previous Failed Attempts:
1. Carbide Reamers: Initially, the client attempted to use standard carbide reamers. By tweaking cutting parameters, they could occasionally meet the requirements, but the process completely lacked stability, and unacceptable scratches frequently appeared inside the bore.
2. Adjustable Brazed PCD Tools: They later switched to an adjustable tool solution featuring brazed PCD with a single breaker edge. However, this introduced a host of new problems:
● Poor Roundness: Asymmetrical cutting edges led to geometric inaccuracies.
● Edge Chipping: Chips easily packed and clogged around the adjustment screws, causing the delicate PCD edges to chip.
● Low Efficiency: The single-breaker-edge design severely limited the feed rate and overall productivity.
Our Innovative Solution: The 6-Flute PCD Dimple Reamer
As a dedicated cutting tool specialist, our core mission is to provide technical solutions to our customers' most demanding machining bottlenecks.
To address the client's core need—balancing high precision with a specific, textured surface finish in poor-machinability forged aluminum—our engineering team integrated advanced process technology with practical production realities. After multiple rounds of custom design and parameter testing, we successfully developed the Custom 6-Flute PCD Dimple Reamer.
Product Highlights & Advantages:
This custom PCD tool features an innovative structure combining 6 cutting edges and 6 pattern-generating breaker edges.
● Perfect Balance & Roundness: The symmetrical 6-flute design eliminates the roundness issues caused by the previous single-edge tool.
● Solid Construction: Eliminating adjustable screws prevents chip clogging and subsequent edge chipping, drastically increasing tool life.
● Unmatched Efficiency: The multi-flute design allows for significantly higher feed rates.
Our PCD Dimple Reamer resolved all previous tooling issues in a single pass. It easily passed on-site testing at the customer’s facility, securing an official order by achieving the dual goals of drastically improved processing efficiency and perfectly stable surface roughness (Rz 2-6 μm).
Technical Application Data
Below are the detailed parameters of this successful machining application:
1. Basic Part Information
● Workpiece Material: Forged Aluminum Alloy
● Material Hardness: HB 120
2. Machining Characteristics
● A fixed, specific surface roughness (Rz 2-6 μm) with a 0.1 mm pitch is required.
● Forged aluminum alloy is notoriously gummy and difficult to machine cleanly without built-up edge (BUE).
3. Application Parameters
● Machine Tool: Mazak Horizontal Machining Center (HMC)
● Our Tool Specification: Custom PCD Dimple Reamer (D20.25 * D20.03 * 110 * L162)
● Machining Allowance: 0.2 mm
● Clamping Method: Fixture Clamping
● Cooling Condition: Internal Coolant (Through-tool)
● Spindle Speed (RPM): 3000 r/min
● Feed Rate: 1200 mm/min
●
Tool Life / Machined Quantity: 12,000 pieces per tool
Struggling with strict surface finish requirements or inefficient reaming operations?
At Moresuperhard, we design and manufacture custom PCD solutions that turn machining challenges into competitive advantages. Contact our engineering team today to optimize your production line.
