Manufacturing process

Surface Treatment

Surface treatment protects and finishes manufactured parts — against corrosion and wear, for appearance, or to meet functional needs such as conductivity, friction or cleanability.

Process overview

Surface treatment modifies or protects component surfaces to meet corrosion, wear, appearance, friction or functional requirements. Processes can include anodizing, plating, coating, blasting, polishing and other chemical or mechanical treatments. Selection depends on substrate material, service environment, required thickness, finish specification, color and applicable testing requirements.

Surface treatments fall into a few families. Conversion and anodic processes change the surface itself: anodising grows a hard oxide layer on aluminium that can be dyed, and passivation helps stainless steel re-form its protective chromium oxide. Coatings add a new layer: powder coating and wet painting for appearance and corrosion protection, hot-dip galvanising and zinc-flake systems for steel, and electroplated zinc, nickel or chrome for corrosion, wear or decorative purposes. Mechanical treatments such as blasting, polishing and shot peening prepare surfaces, change their appearance or introduce compressive stress for fatigue life.

The right treatment depends on base material, service environment, required layer thickness and appearance. Many treatments change dimensions — anodising and plating build up on threads and fits — so masking and allowances should be agreed before machining. Corrosivity categories (for example ISO 12944 for painted steel) and salt-spray requirements are practical ways to specify performance.

Part makers often subcontract finishing, so it helps to state whether the quote should include the treatment or whether parts will be finished separately.

Typical capabilities & what manufacturers can produce

What manufacturers can produce

  • Anodised aluminium parts — clear, coloured or hard anodised
  • Powder-coated enclosures, frames and machine parts
  • Hot-dip galvanised structural steel
  • Zinc, zinc-nickel, nickel and chrome electroplated parts
  • Passivated and electropolished stainless components
  • Blasted, polished and shot-peened surfaces

Capabilities under this process

Suitable materials

Materials commonly used with this process — an editorial reference, not a statement about facilities in the Metraxio network. Suitability always depends on the part and its application.

  • Aluminum

    Anodising, conversion coating and powder coating.

  • Carbon Steel

    Galvanising, zinc plating, powder coating and painting.

  • Stainless Steel

    Passivation, pickling and electropolishing.

  • Alloy Steel

    Plating and black oxide for machine components.

  • Brass

    Nickel and chrome plating for decorative and functional parts.

  • Copper

    Tin and silver plating for electrical contacts.

  • Titanium

    Anodising for colour coding, for example on medical parts.

  • Zinc

    Plating and painting of die-cast parts.

  • Magnesium

    Conversion coatings and painting for corrosion protection.

Relevant industries

Industries whose Metraxio industry guides list Surface Treatment as a common process, with the typical use in each.

What buyers should specify

The details that make Surface Treatment quotes comparable and let facilities be assessed on the right criteria.

Treatment and specification
For example anodising to MIL-A-8625 Type II or III, zinc-nickel to ISO 19598, or a named powder-coating system.
Base material
Alloy and condition — they affect process choice and final appearance.
Layer thickness
Required coating or layer thickness range in µm.
Colour and appearance
RAL or colour sample, gloss level, texture and visible faces.
Masking
Threads, bores, contact and earthing surfaces that must stay uncoated.
Performance tests
Salt-spray hours, adhesion tests and thickness measurement reports.
Chemical compliance
RoHS and REACH requirements, for example hexavalent-chromium-free processes.

On Metraxio these details become a structured manufacturing requirement. Processes, capabilities, materials, certifications and part size are checked against facility profiles; tolerances, finishes and inspection details travel with your drawings and are reviewed during quoting rather than used as automatic filters.

Frequently asked questions

Anodising or powder coating for aluminium?

Anodising becomes part of the surface, keeps a metallic look and adds little thickness. Powder coating gives a thicker, opaque layer in many colours and can hide surface marks. Appearance, wear and corrosion needs decide.

Does a coating affect tolerances?

Yes. Plating and anodising add thickness on all exposed surfaces, including threads and bores. Specify whether dimensions apply before or after treatment, and mask critical features.

What does passivation do?

Passivation removes free iron and contamination from stainless steel surfaces and supports formation of the natural chromium oxide layer, improving corrosion resistance without noticeably changing appearance.

Start a Manufacturing Project

Upload a drawing or describe what you need. Process context from this page can be reviewed before it becomes a structured requirement.

Suggested process is prefilled for review — you can change it.