Aoshiji® Custom Tool – High-Precision PCD Reamer with Unequal Helix Six-Flute Design for Thin-Wall Machining and Superior Roundness
Thin-wall machining requires exceptional stability and accuracy. In this article, we present Aoshiji® Custom Tool’s high-precision PCD reamer with an unequal helix six-flute design—engineered to improve roundness, reduce vibration, and ensure consistent performance in demanding thin-wall applications.
The operating principle of an automotive electric fuel pump begins when the motor is energized, driving the internal rotor to rotate at high speed. The lower end of the rotor shaft engages with the impeller bore, causing the impeller to rotate synchronously. During rotation, the impeller generates a vacuum at the fuel inlet, draws in filtered fuel, pressurizes it, and delivers it through the housing outlet to the fuel system.
Most modern automotive fuel pumps use a vane-type (impeller-type) structure, ensuring efficient fuel delivery and stable pressure output. In this article, we introduce how our High-Precision PCD Reamer with Unequal Helix Six-Flute Design provides a reliable finishing solution for the thin-wall motor bore in this pump assembly.
Workpiece: Oil Pump
Material: ADC12 (Aluminum Die Casting)
Machine Tool: Vertical Machining Center
Coolant Method: Internal Cooling
Machining Area: Motor Bore
Part Drawing:
This component is a thin-walled part, which is prone to deformation during clamping, significantly increasing the difficulty of finishing operations.
The roundness requirement for the bore is highly stringent: for diameters above 60 mm, the roundness must be ≤0.015 mm. Under thin-walled conditions, not only clamping forces but also thermal effects can impact the dimensional accuracy and roundness.
After the bore machining is completed with precision reamers, the outer surface of the part still requires external turning on a lathe, which may further affect the bore roundness and consistency.
04 Optimized Tooling Solution with High-Precision PCD Reamer with Unequal Helix Six-Flute Design
Design Features
The two bores of the fuel pump component require different surface roughness levels, yet both demand strict roundness and tight tolerance control. Combined with the machine’s BT30 spindle, the tooling solution must support fine adjustment while maintaining a lightweight structure. This is why the High-Precision PCD Reamer with Unequal Helix Six-Flute Design was selected as the core finishing tool.
The tool utilizes a flange-holder structure with six unevenly spaced cutting edges, providing excellent roundness accuracy and stable dimensional control during thin-wall machining. The flange holder also allows precise adjustment to compensate for spindle runout, preventing bore-size drift and roundness deviations.
The customer’s original cutting parameters were conservative (approximately S300, F30), resulting in longer cycle times. With the optimized tool geometry and unequal helix design, the new solution achieves significantly higher machining efficiency while maintaining the required precision.
Cutting Parameters:
Tool Diameter: D67 + D62
Spindle Speed: S1000 r/min
Feed Rate: F800 mm/min
In conclusion, the High-Precision PCD Reamer with Unequal Helix Six-Flute Design developed by Aoshiji® Custom Tool has proven to be a breakthrough solution for customers requiring guaranteed roundness in high-precision boring. Its unequal helix geometry effectively suppresses cutting vibration and stabilizes tool engagement—an essential advantage when machining thin-walled components that are highly sensitive to clamping deformation. This advanced design enables the tool to consistently deliver exceptional dimensional accuracy and superior surface quality, even under demanding finishing conditions.
As discussed in our previous article “Aoshiji® Custom Tool – Reverse Taper End Mill for Steering Knuckle Machining Applications”, our engineering approach focuses on solving real-world challenges with practical, results-driven tool designs. The new reamer has not only met the customer’s strict roundness requirements but also delivered excellent performance with cutting parameters optimized for consistency and repeatability.
To further enhance hole-finishing operations, our product line also features the 6-Flute Step PCD Reamer Head – High-Accuracy Hole Finishing and the 3-Flute PCD Reamer with Shank – Precision Diamond Hole Finishing | Aoshiji® Custom Tool, providing versatile solutions for multi-diameter and high-accuracy applications.
Just as leading manufacturers like Sandvik Coromant and MAPAL continue to advance global standards in precision reaming, Aoshiji® Custom Tool remains committed to delivering high-performance PCD solutions that empower customers to overcome complexity, reduce machining risk, and achieve world-class results.
By choosing Aoshiji® Custom Tool’s unequal helix PCD reamer, customers gain more than just a cutting tool—they gain a proven engineering solution to stabilize thin-wall boring, secure roundness accuracy, and unlock greater confidence in precision manufacturing.
