Finishing
Anodizing vs Bead Blasting Aluminum: Finish, Corrosion, and Cost
Anodizing vs bead blasting for aluminum parts: how each changes finish, corrosion resistance, dimensions, and cost, plus a practical decision checklist.
Finishing & QC
CNC Surface Finishing & Inspection Services
In-house at our Dongguan facility, with dimensional inspection by optical measuring systems, height gauges and calipers.
Overview
Surface Finishing
Finishing is where a lot of machining projects go wrong, usually because it was specified without thinking about how it changes dimensions. Anodizing adds thickness — roughly half of it builds outward — so a 25 µm Type III coat changes a bore by about 12 µm per side. On a Ø20 H7 bore, that matters.
Plan the Finish Before the Final Cut
We ask about finishing at quote stage and adjust the machining allowance to suit. Plated threads get pre-plate thread tolerances. Bores that will be hard anodized get machined to suit the finished size, not the pre-coat size. It is a small piece of planning that avoids the most common cause of parts that will not assemble.
Inspection After Finishing
Every finished batch is checked with in-house dimensional inspection after coating, not before. Inspection reports on critical dimensions are available for production orders.
Equipment
Machines Behind This Process
| Finish | Typical Spec | Best For |
|---|---|---|
| Clear / colour anodizing | Type II, 5–25 µm | Aluminium cosmetics and corrosion |
| Hard anodizing | Type III, 25–50 µm | Wear surfaces on aluminium |
| Bead blasting | Ra 0.8–3.2 µm uniform matte | Hiding tool marks, grip surfaces |
| Black oxide | 1–2 µm | Mild corrosion + low-glare finish |
| Zinc plating | 5–20 µm | Corrosion protection on steel |
| Laser engraving | Part marking | Logos, part numbers, serialisation |
What We Make
Typical Parts & Scope
- Anodizing in clear, black and custom colours
- Bead blasting for a uniform matte surface
- Black oxide for mild corrosion resistance and a low-glare finish
- Zinc plating for steel parts
- Laser marking, part numbers and serialisation
Related
Other Capabilities
01
CNC Milling
3-axis and 4-axis vertical machining centres for brackets, housings, plates and enclosures, from one-off prototypes to repeat batches.
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02
CNC Turning
Standard CNC lathes and live-tool turning centres up to Ø380 mm swing. Shafts, bushings, fittings, connectors and threaded components turned complete in one setup.
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03
5-Axis Machining
5-axis machining centre (U400A) for complex, multi-face geometry in one setup. Angled features and compound surfaces finished in a single clamping.
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Insights
Related Articles
Finishing
Surface Finish Ra: What the Number Means and How Machining Controls It
Why Ra alone does not describe a surface, how cutter path, stepover, and nose radius drive finish, and where a surface grinder is the only right tool.
Process
High-Speed Machining Aluminum: Feeds, Speeds, and Chip Thinning
High-speed machining aluminum cuts cycle time with shallow engagement, high spindle speeds, and chip thinning. The tooling and toolpaths that work on 6061.
Ready to Machine Your Part?
Send your drawings and requirements. Quote, lead time and DFM feedback by email.