1. Machine Selection and Technical Characteristics

Based on the structural features and precision requirements of crescent‑shaped liquid cooling connectors, a high‑precision Swiss‑type CNC lathe equipped with multi‑axis interpolation should be selected. The machine must have a sufficient number of controlled axes to integrate and coordinate various machining methods. A coaxial multi‑tool post design allows overlapping operations of multiple tool posts. Together with precise indexing of the spindle, this effectively reduces idle travel time and significantly improves the overall machining cycle.

Swiss‑type lathes offer remarkable advantages in the field of precision shaft‑type parts. They can be fitted with automatic bar feeders to achieve fully automated mass production on a single machine, thereby lowering labour costs and reducing defect rates. For thread cutting and sealing‑surface finishing, a high‑accuracy CNC system and drive units are the key to ensuring the connector’s sealing performance and system reliability. Particularly in liquid cooling systems, the machining accuracy of the connector’s internal bore and the surface quality of its sealing faces directly determine the system’s leak‑tightness and service life.

2. Material Selection and Cold‑Forging Pre‑treatment

Liquid cooling connectors are typically made from metals with high corrosion resistance and good thermal conductivity. Nickel‑plated brass, aluminium alloys and stainless steel are the most common choices. Before batch production, cold forging or hot forging can be used to pre‑form the bar stock into a hexagonal blank close to the final shape. This pre‑treatment strategy not only improves material utilisation and reduces cutting allowance but also creates a denser, continuous metal grain flow, enhancing the mechanical strength of the component.

3. One‑Setup Multi‑tasking Machining Process

A Swiss‑type lathe can perform external turning, internal boring, thread milling, side‑feature machining and other operations in a single clamping. When machining crescent‑shaped liquid cooling connectors, it is essential to arrange the sequence of operations logically. The following principles should be followed:

• External before internal – machine the external cylindrical surface and the hexagonal profile first to establish a stable datum, then proceed to cut internal bores and flow channels.

• Roughing before finishing – leave an appropriate finishing allowance after roughing, then use high‑precision tools to finish critical areas such as sealing faces and threads, ensuring stable control of dimensional tolerances and surface roughness.

• Special tooling for the crescent shape – for the non‑standard crescent recess, a custom‑made solid carbide form mill with a crescent‑shaped cutting edge should be used to ensure accurate geometry and precision.

In addition, for deep bores inside the flow channel, the sub‑spindle should be used for synchronous clamping, allowing the main and sub‑spindles to switch grip and perform simultaneous machining on both ends. By working the main and sub‑spindle channels independently and in parallel, the cycle time is effectively reduced, and the symmetrical end faces as well as related dimensions of the crescent slot are finished precisely.

4. High‑Precision Deep‑Hole Machining and Chip Evacuation Strategy

A high‑pressure coolant‑through‑spindle system (through‑the‑spindle coolant) should be used together with high‑speed cutting tools. Coolant is delivered directly to the cutting edge via the spindle’s internal channel, effectively removing chips and debris from the deep hole and the bottom of the cutting zone, preventing chip packing or entanglement.

For deep holes with a large length‑to‑diameter ratio, a peck drilling cycle should be employed – i.e., retracting the drill after each short depth of cut – to achieve efficient chip breaking and assisted chip evacuation, thereby avoiding the risk of tool clogging or even breakage. Combined with a circulating, filtered, high‑performance coolant system, this strategy significantly improves the surface finish of deep holes, extends tool life, and shortens the total part machining cycle.

5. Finishing Operations and In‑process Quality Monitoring

To ensure the surface quality of the sealing mating faces of the crescent‑shaped liquid cooling connector, the critical sealing surfaces must be high‑precision polished or fine‑ground so that the surface roughness is reliably controlled within the design requirements. All thread features are fully milled using high‑precision thread milling tools to achieve precise profiles.

After all machining steps, the workpiece must undergo ultrasonic cleaning and specialised precision decontamination to completely remove metal chips and oil residues. This satisfies the cleanliness and sealing requirements of liquid cooling systems and fundamentally eliminates system failure risks caused by internal bore leakage of the liquid cooling connector.