As-machined
The default finish straight off the machine, typically Ra 1.6–3.2 µm with light visible tool marks.
Process · CNC machining
Finishing solutions
Surface finishing for your parts
A broad range of finishes to improve the performance and appearance of your parts. Each is selected by material, function and appearance requirement - so the treatment suits its application.
Anodizing
Type II and hard-coat anodizing create a protective oxide layer on aluminium for corrosion resistance, wear resistance and color.
Process · CNC / die casting
Polishing
Mechanical polishing reduces roughness to a bright, smooth or mirror surface for cosmetic and high-spec parts.
Process · CNC / die casting
Bead / sand blasting
Blasting media give a uniform matte texture, removing tool marks and evening the surface before or after coating.
Process · CNC / die casting
Tumbling / deburring
Vibratory tumbling deburrs and smooths small parts in bulk, rounding sharp edges and evening the surface.
Process · CNC / die casting
Specify your finish, color, gloss and any masking requirements on your drawing, or describe the function the surface must perform and we will recommend a suitable treatment at DFM review.
Request a finishing quote
Inspection acceptance
Appearance inspection & acceptance standards
Every finished surface is inspected under controlled conditions against clear acceptance criteria - so coverage, texture, gloss and color stay consistent across the whole batch.
- Anodized, plated or coated surfaces match the agreed color reference or approved sample within a defined tolerance.
- Brushed and grained finishes run in one consistent direction at a uniform grit across the part.
- Cosmetic surfaces are checked for scratches, pits, dents, blisters and other defects against agreed acceptance criteria.
- Gloss and texture stay within the agreed range, checked against a master sample before release.
Visual inspection standard
- Parts are inspected under controlled lighting to assess batch-to-batch consistency against the approved sample.
- Critical cosmetic surfaces are viewed at a defined distance and angle against the approved sample.
- Surfaces must be free of fingerprints, oil, watermarks and residue, and show no undesired discoloration.
- Packaging is checked at final inspection to keep the finish stable and protected in transit.
The basics
What is surface finishing?
Surface finish describes a part’s outer surface after machining, whether left as-machined or treated to change its texture, hardness, corrosion resistance or appearance. Surface roughness (Ra) is one common measure, while the finish also affects how a part seals, wears, conducts, reflects light and resists its environment.
On precision parts, the finish is part of the specification, not an afterthought. The right treatment can improve functional performance and help meet dimensional and assembly requirements, while providing the appearance and protection the application needs.
Common questions
Surface finishing FAQs
How do I choose the right finish for my part?
Start from the surface's job — corrosion protection, wear resistance, conductivity, appearance or marking — plus the base material and any color or gloss target. Tell us the function, or specify the finish on your drawing, and we'll recommend a suitable treatment at DFM review.
What does "anodized" actually mean, and how do you anodize aluminum?
Anodizing means electrochemically thickening aluminum's natural oxide layer to improve corrosion resistance, wear resistance and color. The aluminum part is submerged in an acid bath and an electric current is passed through it to grow this layer — Type II gives a standard finish, hard-coat (Type III) gives a thicker, harder layer for wear-critical parts.
Do you offer black oxide or blackening coatings beyond anodizing?
Yes — black oxide (also called blackening coating) is a thin, low-cost conversion coating suited to ferrous metals like steel, giving a matte black finish with mild corrosion resistance. It adds minimal thickness, making it a good option for parts where anodizing isn't applicable, such as steel components.
Can you plate parts — gold, nickel, or electroless nickel?
Yes, we offer plating including gold plating for connectors and contacts, and electroless nickel plating for a uniform, corrosion-resistant coating even on complex internal geometries that electroplating can't reach evenly. Tell us the functional requirement — conductivity, wear, or corrosion resistance — and we'll confirm the right plating type.
Are all finishes suitable for every material?
No — anodizing only works on aluminum, while stainless steel and titanium form their own natural oxide layer and typically use passivation instead. Chem film treatments like alodine work on aluminum for corrosion protection with minimal thickness. Tell us your material and we'll confirm which finishes apply.
What's the difference between metal polish and mechanical polishing here?
What we do is mechanical polishing using progressively finer abrasive compounds and controlled pressure to reduce surface roughness to a bright or mirror finish — different from a hand-applied metal polish or polishing compound meant for maintenance, which only cleans and shines an already-finished surface rather than removing material to change roughness.
Do you offer laser marking or powder coating as well?
Yes — laser marking is available for permanent part numbers, logos or serial identification, and powder coating is an option for parts needing a thicker, durable colored coating beyond what anodizing provides. Let us know if either fits your project.
Can I apply more than one finish to a part?
Yes — for example, bead blasting or sand blasting to even the surface before anodizing, or vibratory deburring to round edges before a cosmetic polish. We sequence multi-step finishing so each process supports the next rather than undoing it.