Surface treatment & coating
Part of the Metallurgy & Metalworking sector
Surface treatment and coating protect and finish metal parts — plating, anodising, powder coating, galvanising, passivation and heat treatment. This hub explains the main processes and how to find and compare verified coating suppliers on Digibition.
Looking to source in this sector, or want your company to appear here? Browse the directory or list your company.
Overview
Surface treatment changes the outer layer of a metal part to resist corrosion and wear, improve appearance, or add electrical, decorative or functional properties. Common processes include electroplating (zinc, nickel, chrome, tin), anodising of aluminium, hot-dip and electro galvanising, powder coating and wet painting, passivation of stainless steel, phosphating, and heat treatments such as hardening and nitriding.
These are applied finishes rather than materials, so the supplier is defined by the processes it runs, the substrates it accepts, the coating thicknesses and specifications it can meet, and the size of parts its tanks or lines can take. Many finishers specialise — for example in decorative plating, technical hard chrome, or architectural powder coating.
Buyers here include fabricators, machine shops, automotive and construction suppliers, and manufacturers of fasteners and hardware. On Digibition, surface finishing companies publish verified profiles describing their processes and capacity, so professional buyers can discover and compare them by specialization and country.
What to check when sourcing
Surface treatment is a contract service, so you are buying a specified finish. Start with the process and the substrate — the coating must suit the base metal — then the coating specification and thickness, the colour or appearance where relevant, and the corrosion or wear performance the application demands.
Clarify the maximum part size and batch capacity the line can take, how the finish is verified (thickness measurement, adhesion and salt-spray testing), and whether the supplier can meet the standard your sector references. Agree a first-article or sample approval before a series, and ask for inspection or test documentation where the finish is critical.
Use the directory to shortlist suppliers by specialization and country, then contact several and compare process, capacity and testing before you commit.
What to check when sourcing surface treatment & coating
| Criterion | What to look for |
|---|---|
| Process | Plating, anodising, galvanising, powder coating, passivation or heat treat |
| Substrate | Compatibility of the finish with your base metal |
| Specification | Coating thickness, colour and the standard your sector references |
| Performance | Corrosion and wear performance, e.g. salt-spray hours required |
| Part size & batch | Maximum part size and batch capacity the line can handle |
| Testing & approval | Thickness, adhesion and salt-spray testing and first-article approval |
Frequently asked questions
- What is the difference between plating and powder coating?
- Plating deposits a thin metallic layer (such as zinc, nickel or chrome) onto a part, usually by an electrochemical process, for corrosion resistance or appearance. Powder coating applies a dry polymer powder that is cured into a durable paint-like film. The right choice depends on the look, protection and conductivity needed.
- What does anodising do?
- Anodising grows a controlled oxide layer on aluminium, increasing corrosion and wear resistance and allowing colour dyeing. It is widely used for architectural, consumer and technical aluminium parts. The layer thickness and type are specified to match the application.
- How is coating quality checked?
- Finishers commonly verify coating thickness, adhesion and corrosion resistance — for example through salt-spray testing to a defined number of hours — against the specification. Agree which tests and documentation you need before production so the supplier can plan for them.
- How do I find surface treatment suppliers?
- Use the Digibition directory to filter by this specialization and by country, then open each company profile to review its processes, certifications and specializations. You can message suppliers directly, or add several to a quote list and request quotes from all of them at once.
- What should I check before placing a production order?
- Confirm the process suits your substrate, the coating specification, thickness and performance, and the maximum part size and batch capacity. Agree the testing, documentation and first-article approval before a series run. This is general information, not legal or technical advice.
Looking to source in this sector, or want your company to appear here? Browse the directory or list your company.
Important notice
This page is general industry information published by Digibition for educational purposes only. It is not legal, financial, tax, customs, regulatory, or other professional advice, and it is not a substitute for advice from a qualified professional. Standards, certifications, duties, taxes, and regulatory requirements differ between countries and markets and change over time; nothing here is guaranteed to be accurate, complete, or current. Verify any requirement independently with a qualified adviser and the relevant competent authority before you act. Digibition is an online company directory and digital-fair platform; it is not a party to any transaction between users and does not endorse, guarantee, or accept responsibility for any third-party company, product, claim, or certification. A company being reviewed or approved for listing refers only to Digibition's internal listing review and is not a warranty of that company's quality, legality, solvency, or performance. Any mention of specific standards or certifications is illustrative and is not an endorsement or a statement of compliance. To the fullest extent permitted by applicable law, Digibition accepts no liability for any loss or damage arising from reliance on this page; any reliance is at your own risk.