Surface Finishing
Services
Anodizing (CNC), vapor smoothing (3D prints) and powder coating (sheet metal).
Better wear, corrosion resistance, and aesthetics controlled down to Ra 0.012 µm.
Aluminum, Stainless Steel, Carbon Steel, Titanium, Copper, Plastics, and Composites.
ISO 9001:2015 certified process control, RoHS & REACH compliance, and full roughness testing.
What is Surface Finishing?
Surface finishing is any post-manufacturing process that modifies a part's surface for corrosion protection, wear resistance, electrical conductivity, cosmetic appearance, or regulatory compliance. XC Machining applies finishes to aluminum, steel, stainless steel, titanium, copper, brass, and engineering plastics produced by CNC machining, sheet metal fabrication, injection molding, or 3D printing.
XC Machining finishes parts in-house—no outsourcing to third-party finishing shops. This means your finish specification is controlled by the same team that machined or molded your part, maintaining dimensional accuracy and eliminating handling damage from inter-facility transport.
Surface Roughness &
Technical Specification Table
Representative roughness levels (Ra) and dimensional tolerances for key finishing processes:
| Finishing Process | Surface Roughness (Ra) | Dimensional Thickness Change | Primary Application / Benefit |
|---|---|---|---|
| As Machined (Standard) | Ra 1.6 - 3.2 µm | 0 µm | Standard structural and internal mechanical components |
| Bead Blasting | Ra 1.6 - 3.2 µm | Minimal (<2 µm) | Uniform matte cosmetic finish, eliminates tool marks |
| Anodizing Type II | Ra 0.8 - 1.6 µm | +5 to +15 µm | Corrosion resistance, decorative color options |
| Anodizing Type III (Hardcoat) | Ra 0.8 - 2.0 µm | +25 to +50 µm | Extreme wear resistance, high hardness for heavy duty parts |
| Electroless Nickel Plating | Ra 0.4 - 1.2 µm | +5 to +25 µm (uniform) | Uniform coating for complex internal cavity geometries |
| Passivation / Chem Film | Unchanged | 0 µm (microscopic) | Corrosion resistance without changing part dimensions |
| Precision Polishing (SPI A-1) | Ra 0.012 - 0.05 µm | -1 to -5 µm removal | Optical lenses, mold cavities, high-cosmetic panels |
| Powder Coating | Smooth to Textured | +50 to +120 µm | Heavy duty outdoor and cosmetic enclosure protection |
Most Common Surface
Finishes at XC Machining?
XC Machining applies the following surface finishes to CNC machined, sheet metal, injection molded, and 3D printed parts.
Brushing
Brushing creates a directional satin grain at Ra 0.4–0.8 μm on aluminum and stainless steel using 120–400 grit abrasive belts. Produces linear or circular patterns. Compatible with aluminum, steel, stainless, titanium, brass. Applications: consumer electronics panels, appliance faceplates, architectural hardware.
Black Oxide Coating
Black oxide deposits a 0.5–1.5 μm magnetite (Fe₃O₄) conversion layer on steel and stainless steel parts without dimensional change. Provides a matte black appearance, mild corrosion resistance (50–100 hr salt spray with oil), and improved lubricity. Applications: fasteners, gears, firearms components, hand tools.
Passivation Process
Passivation per ASTM A967 removes free iron from stainless steel surfaces using nitric or citric acid, forming a chromium-rich oxide layer. No dimensional change or surface finish change. Enhances corrosion resistance for medical, food-grade, and chemical-exposure applications.
Painting
Industrial spray painting with polyurethane, epoxy, or enamel topcoats for custom RAL and Pantone color matching. Delivers smooth satin or glossy cosmetic finishes with enhanced UV and environmental resistance for enclosures and display housings.
Polishing
Mechanical mirror buffing and diamond paste lapping achieves ultra-low surface roughness down to Ra 0.012 μm. Essential for optical light guides, hydraulic sealing surfaces, injection mold core cavities, and luxury cosmetic hardware.
Alodine Coating
Chromate conversion coating per MIL-DTL-5541 providing exceptional corrosion resistance while preserving electrical conductivity on aluminum substrates. Serves as an ideal primer base for paint or powder coat adhesion.
CNC Machining Materials
Aluminum
Lightweight, corrosion-resistant, and highly machinable for precision and structural parts. Accepts Type II & Type III anodizing in clear, black, red, and blue color dyes.
Surface Finishing Prototype
Manufacturing Capabilities
At XC Machining, we pride ourselves on being the go-to manufacturer for all your Surface Finishing needs, providing reliable and efficient solutions under one roof.
CNC Machining
Milled and turned precision parts with controlled Ra 0.8–3.2 µm finishes.
Injection Molding
SPI standard A-1 mirror polished and textured mold core finishes.
Value Added Services
Laser engraving, custom masking, Helicoil inserts, and clean packaging.
Metal Fabrication
Sheet metal deburring, graining, powder coating, and silk-screening.
XC Machining’s Surface Finishing
Process Work Step by Step?
Upload the Design File
Upload your STEP, STP, STL, or IGES file along with your surface finish specification. If you're unsure which finish to select, our engineers will recommend the optimal option based on your material, application, and cosmetic requirements.
Automated DFM & Masking Review
Our engineering team reviews your drawings to account for plating thickness growth, identify critical threaded holes for masking, and verify Ra surface roughness parameters.
In-House Surface Application
All surface finishing processes are executed in our certified facilities with automated bath temperature control, strict chemistry monitoring, and zero third-party transit delays.
100% Quality & Profilometer Inspection
Finished components undergo surface roughness testing (Ra/Rz profilometer), adhesion cross-hatch testing, and salt-spray validation before final protective packaging.
Solutions For Every
Industries Served
Get a Quote
Aerospace
Certified aerospace components built for mission-critical performance and full traceability.
Frequently Asked
Questions
Have a questions? We've made it easy. Here's what to know before ordering and what you are looking for feel free to ask.
Yes. XC Machining ships CNC machined and manufactured parts to 120+ countries via DHL, FedEx, and UPS with full tracking and customs documentation included.
Let’s bring your
vision to life
We are here to make sure you feel confident and supported throughout your journey with us.