Hello, I’m aware of the 720 rule for anodizing, but I’m struggling to apply it effectively to the design of my aluminum components for an optical system. These parts require Type III hard anodizing for improved wear resistance and surface hardness. The most critical component is a mounting bracket with complex geometries, including several thin walls and deep pockets.

There are several deep, narrow pockets (aspect ratio up to 5:1) that are crucial for the optical alignment. How can I ensure uniform anodizing thickness in these hard-to-reach areas? The part also has several threaded holes (M3 and M4) that need to remain functional after anodizing. What’s the best approach to protect these features while ensuring good anodizing coverage on adjacent surfaces?