A stamped part is rarely finished the moment it leaves the press. Surface finishing protects it from corrosion, sets its appearance and can change how it conducts electricity, and the best choice depends on both the metal and the function.
This guide compares the most common finishes for stamped and fabricated metal parts so you can specify the right one in your RFQ.
Why finishing is part of the design
Finish affects corrosion resistance, appearance, conductivity, assembly handling and inspection. It should be planned before production, because coating thickness, masking and color can all affect fit and cost. Treating finish as an afterthought is a common source of late changes.
Powder coating
Powder coating applies a dry powder electrostatically, then cures it into a tough colored film. It is durable, comes in a wide color range and is a common choice for visible steel enclosures, brackets and chassis. Because it adds measurable thickness, areas that need electrical contact or a tight fit should be masked.
Plating
Plating deposits a thin metal layer on the surface. Because it is thin, it preserves dimensions better than powder coating, which matters on precise features.
- Zinc: low-cost corrosion protection, common on steel.
- Nickel: hardness, appearance and corrosion resistance.
- Tin: solderability and conductivity for electrical parts.
Anodizing
Anodizing is an electrochemical process that thickens aluminum's natural oxide layer for better wear and corrosion resistance and a clean appearance, and it can be dyed in a range of colors. It applies to aluminum rather than steel, and is common on aluminum enclosures, covers and heat structures.
Brushing, polishing and silkscreen
Some finishes are about appearance and labeling rather than protection. Brushing creates a directional satin texture, polishing produces shine, and silkscreen prints graphics or markings on product-facing surfaces. These are often combined with a protective finish.
Matching finish to material
Material narrows the choices before anything else. Bare steel needs a finish such as powder coating or plating; aluminum is often anodized but can also be powder coated; stainless steel may need no coating but can be brushed for appearance; copper and brass are usually plated.
How to specify a finish in your RFQ
A clear finish requirement avoids rework and helps the quote reflect the real production route.
- Finish type and any applicable standard.
- Color, gloss or texture where it matters.
- Masked or no-coating zones marked on the drawing.
- An appearance sample when exact color or texture is critical.
| Finish | What it does | Best materials | Watch-outs |
|---|---|---|---|
| Powder coating | Durable colored protective film | Steel, aluminum | Adds thickness; mask contact areas |
| Zinc plating | Low-cost corrosion protection | Steel | Thin; limited appearance options |
| Nickel plating | Hardness, appearance, corrosion resistance | Steel, copper, brass | Higher cost than zinc |
| Tin plating | Solderability and conductivity | Copper, steel | Soft surface |
| Anodizing | Hard, corrosion-resistant oxide layer | Aluminum only | Not for steel; color range limited |