Surface Finishing for CNC Machined Parts

Improve corrosion resistance, wear resistance, appearance, and functional performance with surface finishing options for custom CNC machined parts.
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Wide Range of Surface Finishes
Consistent Quality & Appearance
Machining & Finishing Support
Surface finishing options for CNC machined parts
SURFACE FINISHING SERVICES

Surface Finishing Options

Choose from a range of surface finishes for corrosion protection, wear resistance, appearance, and functional requirements.
As-machined CNC aluminum part with visible machining marks

As-Machined

As-machined parts retain the surface produced directly by CNC machining, with visible tool marks and no secondary finishing process.
Suitable Materials
Aluminum, Stainless Steel, Steel, Brass, Titanium, Engineering Plastics
Main Benefits
Short lead time, lower cost, no secondary finishing
Typical Surface Roughness
Ra 1.6–3.2 μm typical, depending on process and tooling
Color Options
Natural material color
Appearance
Visible machining marks / Natural finish
Typical Applications
Prototypes, functional components, internal parts, fit-check parts
Purple anodized aluminum CNC machined part

Anodizing

Anodizing forms a controlled oxide layer on aluminum surfaces to improve corrosion resistance, wear resistance, and appearance, with multiple color options available.
Suitable Materials
Aluminum 6061, 6063, 7075, and other suitable aluminum alloys
Main Benefits
Corrosion resistance, wear resistance, decorative appearance
Typical Thickness
5–25 μm
Color Options
Clear, Black, Red, Blue, Gold, Green, Purple, and custom colors
Appearance
Matte / Satin / Gloss
Typical Applications
Enclosures, brackets, housings, automation components, and visible parts
Bead blasted aluminum CNC machined part with matte finish

Bead Blasting

Bead blasting creates a uniform matte surface, reduces visible machining marks, and prepares parts for anodizing or other subsequent finishes.
Suitable Materials
Aluminum, Stainless Steel, Steel, Brass, Titanium
Main Benefits
Uniform matte finish, reduced machining marks, lower glare
Dimensional Impact
Minimal material removal; no coating added
Color Options
Natural material color
Appearance
Matte / Satin / Uniform texture
Typical Applications
Housings, brackets, enclosures, cosmetic parts, anodizing preparation
Black powder coated CNC machined metal part

Powder Coating

Powder coating applies a durable polymer coating to metal parts for corrosion protection, wear resistance, and a wide range of colors and textures.
Suitable Materials
Aluminum, Steel, Stainless Steel
Main Benefits
Durable protection, corrosion resistance, broad color selection
Typical Thickness
50–150 μm
Color Options
Wide range of RAL colors, textures, and gloss levels
Appearance
Matte / Satin / Gloss / Textured
Typical Applications
Enclosures, brackets, machine components, fixtures, and outdoor parts
Electropolished CNC machined metal part with bright surface

Electropolishing

Electropolishing removes a controlled microscopic layer from the metal surface to reduce roughness, improve cleanliness, and produce a smoother, brighter finish.
Suitable Materials
Stainless Steel and selected metal alloys
Main Benefits
Reduced surface roughness, improved cleanliness, enhanced corrosion resistance
Typical Material Removal
Typically 5–25 μm, depending on material and process requirements
Color Options
Natural metallic finish
Appearance
Smooth / Bright / Reflective
Typical Applications
Precision components, fluid-contact parts, clean-surface components, and corrosion-sensitive parts
Passivated stainless steel CNC machined part

Passivation

Passivation removes free iron and surface contaminants from stainless steel, helping restore its protective oxide layer and improve corrosion resistance with negligible dimensional change.
Suitable Materials
Stainless Steel
Main Benefits
Improved corrosion resistance, cleaner surface, negligible dimensional change
Dimensional Impact
Negligible
Color Options
Natural metallic finish
Appearance
No significant visual change
Typical Applications
Precision stainless steel components, fittings, housings, and corrosion-sensitive parts
Black oxide finished steel CNC machined part

Black Oxide

Black oxide is a conversion treatment for ferrous metals that creates a thin black surface layer for improved appearance and mild corrosion resistance with minimal dimensional impact.
Suitable Materials
Carbon Steel, Alloy Steel, Tool Steel
Main Benefits
Black appearance, mild corrosion resistance, minimal dimensional change
Typical Thickness
Approx. 0.5–1.5 μm
Color Options
Black
Appearance
Matte / Satin Black
Typical Applications
Fasteners, shafts, fixtures, tooling components, machine parts
Nickel plated CNC machined part with metallic finish

Nickel Plating

Nickel plating deposits a metallic nickel layer onto machined parts to improve corrosion resistance, wear resistance, and surface durability.
Suitable Materials
Steel, Stainless Steel, Brass, Copper Alloys
Main Benefits
Corrosion resistance, wear resistance, improved surface durability
Typical Thickness
Typically 5–25 μm, depending on specification
Color Options
Natural nickel / Bright metallic
Appearance
Satin / Bright / Metallic
Typical Applications
Shafts, fittings, fasteners, mechanical components, decorative parts
Polished CNC machined metal part with reflective finish

Polishing

Polishing mechanically smooths machined surfaces to reduce visible marks and improve appearance, from satin finishes to highly reflective surfaces.
Suitable Materials
Stainless Steel, Aluminum, Brass, Copper Alloys
Main Benefits
Smoother surface, improved appearance, reduced visible machining marks
Typical Surface Finish
Satin to mirror finish
Color Options
Natural metallic finish
Appearance
Satin / Bright / Mirror
Typical Applications
Decorative parts, housings, fittings, consumer products, visible components
SURFACE FINISH COMPARISON

CNC Machining + Surface Finishing from One Supplier

Compare materials, appearance, dimensional impact, and typical applications to choose the right finish for your CNC machined parts.
Finish
Suitable Materials
Appearance
Thickness / Change
Main Purpose
As-Machined
Most machinable materials
Visible machining marks
No added coating
Functional parts / no secondary finishing
Anodizing
Aluminum alloys
Matte / Satin / Colored
5–25 μm
Corrosion + wear protection
Bead Blasting
Al / SS / Steel / Brass / Ti
Uniform matte
Minimal removal / no coating
Cosmetic uniformity
Powder Coating
Aluminum / Steel / SS
Matte / Gloss / Textured
50–150 μm
Durable protection
Electropolishing
SS / selected metal alloys
Bright / Reflective
Removes 5–25 μm
Smoothness + cleanliness
Passivation
Stainless Steel
Natural metallic
Negligible
Corrosion resistance
Black Oxide
Carbon / Alloy / Tool Steel
Matte / Satin Black
~0.5–1.5 μm
Appearance + mild protection
Nickel Plating
Steel / SS / Brass / Copper alloys
Satin / Bright Metallic
5–25 μm
Wear + corrosion resistance
Polishing
SS / Al / Brass / Copper alloys
Satin / Bright / Mirror
Material removal varies
Appearance + smoothness
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ANODIZING COLORS & SURFACE OPTIONS

Anodizing Colors & Surface Options

Type II anodizing offers a wide range of color options, while Type III hardcoat anodizing provides a thicker, more wear-resistant finish for functional parts.
II
Type II Anodizing
Decorative, protective & colored finishes
III
Type III Hardcoat
Thicker, wear-resistant functional finish
TYPE II ANODIZING COLOR OPTIONS
Clear Type II anodized aluminum sample
Clear / Natural
Black Type II anodized aluminum sample
Black
Red Type II anodized aluminum sample
Red
Blue Type II anodized aluminum sample
Blue
Gold Type II anodized aluminum sample
Gold
Green Type II anodized aluminum sample
Green
Purple Type II anodized aluminum sample
Purple
TYPE III HARDCOAT ANODIZING OPTIONS
Natural gray Type III hardcoat anodized aluminum sample
Natural / Gray
Dark gray Type III hardcoat anodized aluminum sample
Dark Gray
Black Type III hardcoat anodized aluminum sample
Black
Color may vary depending on alloy, surface preparation, anodizing type, and batch conditions.
INTEGRATED MANUFACTURING SUPPORT

Machining + Surface Finishing from One Supplier

We coordinate CNC machining and surface finishing through one manufacturing workflow to simplify sourcing, maintain consistent requirements, and reduce project handoffs.
CNC machined aluminum part before surface finishing
Machined Part
Blue anodized CNC aluminum part after surface finishing
Finished Part (Anodized)
Single-Source Coordination
Consistent Requirements
Simplified Lead Times
Reduced Supplier Handoffs
Process & Inspection Control
SURFACE FINISH QUALITY CONTROL

Quality Control for Consistent Finishes

Pre-Finish Check
Critical dimensions and masking requirements verified before finishing.
Coating Thickness
Coating thickness checked against specified requirements.
Color Consistency
Color and appearance checked across parts and batches.
Appearance Inspection
Surfaces checked for scratches, stains, discoloration, and visible defects.
Post-Finish Check
Critical dimensions rechecked after finishing when required.
Masking Protection
Threads, holes, mating surfaces, and critical areas protected as specified.
FINISHED PARTS GALLERY

Finished CNC Parts Gallery

Need a Specific Surface Finish?

Send us your drawings and finishing requirements. We’ll review the material, finish, color, masking, and critical tolerances before quotation.
SURFACE FINISHING FAQ

Frequently Asked Questions

Find answers about surface finishing options, anodizing, coating thickness, masking, color consistency, and finishing requirements.

We support anodizing, bead blasting, powder coating, electropolishing, passivation, black oxide, nickel plating, polishing, and other finishes based on project requirements.

Anodizing adds a controlled oxide layer to the surface. Critical dimensions and tight-tolerance features should be identified so coating thickness can be considered during machining and finishing.

Yes. Threads, holes, sealing surfaces, electrical contact areas, and other critical features can be masked according to drawing requirements.

Yes. Color samples, reference parts, or specified color requirements can be used as a target. Final color and appearance may vary slightly depending on alloy, surface preparation, anodizing type, and batch conditions.

Please provide drawings or 3D CAD files, material, quantity, required surface finish, color or appearance requirements, coating thickness if specified, masking requirements, and any critical dimensions or tolerances.

Yes. We can coordinate CNC machining, surface finishing, inspection, and delivery through one manufacturing workflow based on your drawings and project requirements.