blind rivets zinc plated solutions
The zinc plated process for Blind rivets is the deposition of a metallic zinc coating on the surface of the blind rivet by electroplating. This process improves corrosion resistance, surface stability and appearance consistency. This process is widely used for carbon steel blind rivets and is one of the most common and cost-effective methods of surface protection in industrial volume manufacturing.
Why blind rivets need to be zinc plated?
zinc plated is a standardized, low-cost, high-performance protection solution that improves the overall suitability and durability of blind rivets. It is therefore used in a wide range of industrial and manufacturing applications.
- Improve the corrosion resistance of blind rivets
- Maintains appearance and dimensional stability
- Lower cost of galvanizing
Types of blind rivets zinc plated
Zinc plated blind rivets are galvanized in a number of different ways. The different types determine the rivets’ corrosion resistance, cosmetic characteristics and the environment in which they are applied. The following are common types of galvanization:
- Trivalent Blue/White Zinc: 72-96 hours without red rust
- Trivalent Yellow/Color Zinc: up to 120-168 hours red rust free
- Sealed Trivalent Zinc: 240-300 hours red rust free
Zinc Plated Process Overview
When black anodizing rivets, it is necessary to ensure that the oxidized film layer is uniform, the dye is full and the holes are sealed thoroughly, in order to achieve stable protection and appearance.
1. Pre-treatment
- Degreasing and degreasing: Use alkaline degreasing agent or ultrasonic cleaning to remove oil and cold working residue.
- Acid washing and descaling: Use dilute hydrochloric acid or sulfuric acid solution to remove surface oxidized skin and rust layer.
- Water washing and neutralization: Use pure water or flowing water to fully clean after each treatment to prevent impurity residue.
2. Surface Activation
Weak acid activation solution (e.g. dilute sulfuric acid) is used to further enhance the electrochemical activity of the surface, laying the foundation for the adhesion of the plating layer.
3. Zinc Plating
This step is commonly used in acidic zinc chloride or alkaline zinc-nickel alloy plating solution. The plating method is by roll plating (barrel plating), which is suitable for small parts and large quantities of rivets to be processed.
Process parameters:
- Current density: 1.0-2.5 A/dm².
- Temperature: 20-30°C
- Time: 10-20 minutes (according to the thickness of the coating)
Plating thickness control: generally between 5-12 μm, depending on the application (refer to ISO 4042, ASTM B633, etc.)
4. Passivation
- Trivalent Chromium Passivation: Blue white zinc or colored zinc commonly used passivation solutions to further improve corrosion resistance and appearance consistency.
- Optional sealing treatment: Use silicone or nano sealer to enhance salt spray performance.
5. Post-treatment
- Cleaning and rinsing: Remove residual chemicals to avoid corrosion at a later stage.
- Centrifugal drying or hot air drying: to ensure that the parts are free of water stains and watermarks, to prevent the return of rust.
Applications of Zinc Plated Blind Rivets
- Home Appliances: metal housings, brackets and connectors for washing machines, refrigerators, air conditioners, microwave ovens, etc.
- Industrial Sheet Metal: Panel fixing and frame connection for distribution cabinets, control boxes, server shells, operation consoles, etc.
- Architectural & Furniture Hardware: Aluminum profile connections, ceiling structures, metal doors and windows, toolboxes, and iron furniture.
- Transportation Equipment: Riveting of shelf brackets, light trailer panels, and structural parts in non-load bearing vehicles.
- Electrical & Electronic Assemblies: fixed wire bridges, heat sinks, brackets, electric control enclosures, etc.
- Hardware & Tools: Used in folding ladders, metal shelves, tool carts, equipment bases and other connection nodes.
Material Compatibility & Limitations
The use of zinc plated surface treatments for blind rivets offers a good price/performance ratio and basic protection. However, there are significant technical and performance limitations in certain design, use and material mix scenarios.
- Limited anti-corrosion rating: the overall anti-corrosion capability of the galvanized layer is not as good as nickel plating, stainless steel or anodized treatment.
- Risk of galvanic coupling corrosion: galvanized rivets may be electrochemically corroded when in contact with dissimilar metals such as aluminum, stainless steel and copper.
- General abrasion resistance of plating: compared with nickel plating or oxidized treatment, zinc layer is softer and prone to flaking or scratching due to friction and impact during assembly or use.
- Limited to carbon steel substrates: Zinc plating is primarily suitable for carbon steel blind rivets.
- Plating thickness is limited: the zinc plating layer is usually controlled at 5-12μm, too thick will affect the precision of the grip size.
- Appearance consistency is limited: slight color difference, hang marks, thin plating on edges and corners may occur in the process of roll plating.
If you are working in a low-corrosion, indoor, ambient temperature environment with no strong potential difference structures, galvanizing is a very cost-effective solution. However, when it comes to exposed structures, high humidity/salt spray, or precision assemblies, nickel plating, stainless steel, or anodizing alternatives should be preferred.
Surface Treatment Comparison – zinc palted blind Rivet vs. Alternatives
| Criteria | Zinc Plated | Nickel Plated | Anodized | Powder Coated | Stainless Steel (Base Material) |
|---|---|---|---|---|---|
| Base Materials | Carbon steel | Carbon steel, brass, copper | Aluminum | Aluminum, steel, stainless steel | Stainless steel only |
| Corrosion Resistance | ★★★☆☆ | ★★★★☆ | ★★★★☆ | ★★☆☆☆ | ★★★★★ |
| Wear Resistance | ★★☆☆☆ | ★★★★☆ | ★★★☆☆ | ★★☆☆☆ | ★★★★☆ |
| Appearance Stability | Moderate, color variation possible | Bright or matte, stable | Matte, oxidation layer stable | Variable colors, prone to chipping | Natural silver metallic |
| Electrical Conductivity | Fair (thin layer) | Good | Insulating | Insulating | Good |
| Cost | Low | Medium | Medium | Medium to high | High |
| Recommended Use | Indoor, light industrial use | Electronics, moisture-prone areas | Aluminum structures, light outdoor | Visible parts, decorative panels | Corrosive, structural, exposed use |
