Step 1: Rough Machining & Contour Preparation

Initial material preparation begins with cutting an AL6061 aluminum rod to size, reserving appropriate machining allowances based on final product dimensions. This establishes the foundation for subsequent processes. The CNC Milling machine then performs rough machining, rapidly removing excess material. Key features such as the main contour, large central opening, and pre-formed flange assembly holes are milled in this phase. Careful control of shape and positional tolerances during rough machining reduces residual cutting stresses and minimizes deformation risks, ensuring optimal conditions for precision finishing.

Step 2: Aging Treatment & Precision Machining

After rough machining, the component undergoes controlled aging treatment to relieve internal stresses accumulated during machining. This step enhances dimensional stability before precision operations. High-precision CNC milling is then applied to achieve exceptional accuracy on the flange face, including the formation of mounting holes and central threaded bore (G2).

• The flange closure surface is machined in one pass, guaranteeing flatness and surface finish quality.
• Rectangular mounting holes are processed through drilling followed by profiling (disc milling), ensuring minimal positional deviation.
• The central G2 thread is produced using a specialized thread milling machine, precisely controlling pitch, profile angle, and diameter—ensuring perfect interchangeability and reliable sealing performance.

Step 3: Surface Finishing & Final Treatments

Post-machining, burrs and sharp edges are carefully removed via deburring to prevent interference during assembly and ensure user safety. The surface treatment process follows:

• Sandblasting: Applied to create a uniform, matte, non-reflective finish while eliminating machining marks and improving adhesion for subsequent coatings.
• Hard Anodizing: A dense, wear-resistant oxide layer is formed on the aluminum surface, significantly enhancing corrosion resistance, abrasion resistance, and electrical insulation properties.

These treatments ensure the end cap maintains stable, high-performance operation even under harsh conditions—including humidity, oil exposure, and extreme temperature variations—over extended service life.