Type II and Type III Anodized Aluminum CNC Components

Parts are machined with finishing allowances that account for anodize growth, and edges are chamfered or radiused so the coating covers corners evenly. Threads and precision bores are masked with plugs or caps if they must stay bare. After machining, parts are degreased, etched and anodized, then dyed and sealed for Type II, or sealed or left unsealed for Type III depending on use.

Type II anodizing is typically 5–25 µm thick and accepts dyes in black, red, blue, gold and other colors. Type III hard anodizing is usually 25–50 µm or more, much harder and more wear resistant, but colors are limited to dark tones. 6061 gives the most consistent results; 7075 is stronger but less uniform in color; casting alloys anodize poorly.

Coating thickness is measured with eddy-current gauges, and color is compared with approved samples. Dimensions are checked after finishing on critical features. Typical parts include appliance knobs and trims, sliding guides, pneumatic cylinder components, camera parts, enclosure panels and robotics parts that need durable, consistent surfaces, whether ordered as single prototypes or repeat production batches with matched color.