Post-Machining Options
Surface Finishes for CNC Machined Parts
Formexi coordinates as-machined, conversion, plating, coating, mechanical finishing, heat treatment and marking for CNC parts. Finish selection should start with function, material and dimensional allowance, then appearance. Most special finishes are completed through qualified partners and reinspected before shipment.

Select a Finish by the Problem It Must Solve
| Buyer objective | Finishes often considered | Important boundary |
|---|---|---|
| Lowest cost and shortest route | As machined, controlled deburring | Tool marks remain visible |
| Aluminum corrosion/appearance | Anodizing, hard anodizing, chemical conversion | Alloy, color and dimensional buildup matter |
| Steel corrosion protection | Zinc plating, electroless nickel, black oxide, paint or powder coat | Environment and coating thickness determine suitability |
| Stainless cleanliness/corrosion support | Passivation, polishing or electropolishing | Does not correct an unsuitable stainless grade |
| Cosmetic texture | Bead blasting, brushing, polishing, painting or powder coating | Approved samples and A/B/C surfaces are needed |
| Identification | Laser marking or approved print/engraving | Content, location, contrast and permanence must be specified |

Finish Must Be Included Before Machining
Coatings add thickness, polishing removes material, heat treatment can distort parts, blasting changes texture, and masking creates transition zones. Critical holes, threads, sealing faces and electrical contacts should be identified before the machining process and dimensions are finalized.
Surface Finish Directory
As Machined
Fastest route with visible machining marks and defined deburring.
Anodizing
Aluminum conversion for corrosion, wear, insulation and appearance.
Plating
Electroless nickel, zinc and project-specific electroplating.
Mechanical Finishing
Bead blasting, brushing and polishing for texture or surface preparation.
Coatings
Powder coating and painting for color and environmental protection.
Information Needed for a Reliable Finish Quote
- Base material, grade and condition
- Finish standard, type, color, gloss and texture
- Required thickness or functional target
- Masking zones, threads and electrical/contact surfaces
- A/B/C cosmetic surfaces and allowed variation
- Certificate, test and measurement requirements
- Approved sample or color standard where appearance matters
Partner Process and Quality Control
Finishing suppliers are selected by process capability and prior performance. The quotation identifies the planned route where relevant. Returned parts are checked for appearance, critical dimensions, masking, quantity and requested documentation before shipment.

How We Control the Buyer Risk in Surface Finishes for CNC Machined Parts
When a finish can change dimensions, hide burrs, create color variation or damage cosmetic and sealing surfaces, late finish decisions can turn acceptable machined parts into rejected final parts. For Surface Finishes for CNC Machined Parts, our engineering and quotation review coordinates machining allowance, pretreatment, masking, rack-contact location, thread and fit protection, handling and post-process inspection as one route. This helps reduce rework, approval delays and avoidable purchasing cost without turning a screening assumption into a capability guarantee.
For the Surface Finishes for CNC Machined Parts buying decision, we confirm the route only after reviewing base material, process type/class, thickness, color or texture sample, masks, critical post-finish dimensions, tests and packaging. Any unresolved item is listed as an RFQ clarification so the buyer can compare scope, evidence, price and lead time on the same basis.
Choose the Finish Before Releasing the Drawing
Send the finished-part requirements with the RFQ so dimensional allowance and inspection are planned correctly.