Surface Finishing
Need custom surface finishing for your parts? ZAK provides in-house powder coating and managed plating, anodizing, specialty finishes for your sheet metal parts. One quality system. One point of contact. Save your time and cost.
✓ ISO 9001 | IATF 16949
✓ Up to 1,000hr Salt Spray
✓ ΔE < 1.0 Color Consistency
✓ 525m Automated Line
Leading companies we support
How Our Surface Finishing Works
Your parts need the right finish to perform in the field, and you need a supplier who’s transparent about how that finish gets applied. Here’s exactly how our surface finishing operation works.
In-House Powder Coating
Our 525-meter automated powder coating line handles the complete finishing cycle inside our Foshan facility — from surface preparation to final cure. Parts enter raw and exit as fully coated, cured, inspected components.
- Line Length: 525m
- Spray System: Gema (Switzerland)
- Daily Capacity: 15,000 m²
- Annual Capacity: 4.68M m²
- Max Part Size: 2,200 × 1,500 × 600mm
- Salt Spray: Up to 1,000hr
- Color Match: ΔE < 1.0
Managed Finishing Network
For finishes beyond powder coating, we coordinate production through vetted finishing partners under our quality management system. You receive one shipment, one quality report, and one invoice.
- Electroplating (zinc, nickel, chrome)
- Anodizing — Type II & Type III
- E-coating (electrophoretic deposition)
- Brushing & polishing (#4 satin to mirror)
- Anti-fingerprint & anti-rust coatings
Our Surface Finishing Capabilities
From corrosion protection to decorative appearance, we offer a complete range of metal surface finishes, applied in-house or managed through our partner network.
Pre-treatment & Cleaning
Integrated 7-stage chemical cleaning and phosphating built into our 525m powder coating line. Alkaline degreasing, acid cleaning, phosphating, and DI water rinse.
Powder Coating
Automated electrostatic powder application with Gema Switzerland guns and thermal cure. Wide RAL, Pantone, and custom color range with ΔE < 1.0 batch-to-batch consistency.
Electroplating
Zinc, nickel, chrome, and other metal deposits for corrosion resistance, conductivity, and decorative appearance. Managed through vetted partners with incoming QC inspection.
Anodizing
Type II (decorative) and Type III (hardcoat) electrochemical oxide layer for aluminum parts. Provides corrosion resistance, wear resistance, and color options through dyeing.
Brushing & Polishing
Mechanical surface texturing from directional brushed grain (#4 satin) to mirror-bright finish (Ra ≤ 0.1μm). Creates premium visual appearance for consumer-facing products.
E-Coating
Electrodeposition coating provides uniform coverage on complex geometries including recesses, internal cavities, and hard-to-reach areas that spray coating can miss.
Protective Coatings
Anti-rust, anti-fingerprint, and functional protective treatments for exterior-facing surfaces. Maintains aesthetic appearance while adding corrosion and contamination resistance.
Need Special Surface Treatment?
Contact with our engineer teams to discuss solutions for you.
Powder Coating: Our In-House Line
Our 525-meter automated powder coating line is the centerpiece of ZAK’s surface finishing operation. Designed for high-volume production programs, it delivers consistent results across millions of square meters per year.
The Line
Our Foshan facility runs a 525-meter automated powder coating line equipped with Gema electrostatic spray guns (Switzerland). The line handles parts up to 2,200 × 1,500 × 600mm and processes up to 15,000 m² per day in continuous production.
Pre-Treatment: 7-Stage Process
Before any powder is applied, parts pass through our integrated 7-stage chemical pre-treatment zone: alkaline degreasing → water rinse → acid cleaning → water rinse → phosphating → water rinse → DI water rinse. This produces a chemically clean, phosphated substrate that maximizes coating adhesion and corrosion resistance from the ground up.
Application & Cure
Powder is applied electrostatically and cured in our thermal oven at controlled temperatures. We run RAL, Pantone, and custom color formulations. Batch-to-batch color consistency is verified with our Konica Minolta CR-400 colorimeter — ΔE < 1.0 is our standard.
Production Programs
Our line runs ongoing production for Honda, Carrier, Midea, Gree, and Weber. These aren’t one-time jobs — they’re multi-year programs with defined color standards, test requirements, and delivery schedules we meet consistently.
| Specification | Value |
|---|---|
|
Line Length |
525 meters |
|
Spray System |
Gema (Switzerland) electrostatic guns |
|
Daily Capacity |
15,000 m² |
|
Annual Capacity |
4.68 million m² |
|
Max Part Size |
2,200 × 1,500 × 600mm |
|
Coating Thickness |
60–120μm |
|
Salt Spray Resistance |
Up to 1,000hr (ASTM B117) |
|
Color Accuracy |
ΔE < 1.0 (CIE Lab) |
|
Pre-treatment |
7-stage phosphating |
|
Color Range |
Full RAL, Pantone, custom |
How We Manage Finishing Quality
For finishes applied at partner facilities, we don’t just hand off your parts and hope for the best. We manage the entire process, from partner qualification to incoming inspection at our facility.
Spec & Source
Finish requirements defined during DFM. We select the partner based on certification, track record, and capability.
Coordinate Production
Parts move from our fab line to the partner on our schedule. We manage logistics and batch tracking.
Incoming Inspection
Finished parts return to our QC lab. Thickness (TC-880), color (CR-400), adhesion (cross-cut), salt spray (HT-YW-90).
Ship Under One Report
One shipment, one report, one invoice. If anything fails, ZAK handles the rework.
Whether your parts are powder-coated in our facility or plated at a partner shop, they pass through the same ZAK inspection lab before they ship. That’s single-source accountability.
How to Choose the Right Surface Finish
The right finish depends on your part’s function, material, environment, and appearance requirements. This comparison can help you narrow down the options and our engineering team can confirm the best choice during your DFM review.
| Criteria | Powder Coating | Electroplating | Anodizing | E-Coating | Brushing |
|---|---|---|---|---|---|
| Corrosion | ★★★★★ | ★★★★ | ★★★★ | ★★★★★ | ★★ |
| Salt Spray | Up to 1,000hr | 96–720hr | 336–1,000hr | 500–1,000hr | N/A |
| Aesthetics | RAL/Pantone | Metallic | Clear/dyed | Limited | Natural |
| Thickness | 60–120μm | 5–25μm | 5–25μm | 15–25μm | N/A |
| Materials | Steel, Al | Steel, Cu, Brass | Al only | All metals | SS, Al |
| ZAK Model | ⭐ In-House | Managed | Managed | Managed | Managed |
Outdoor / Corrosive Environments
Powder coating on our in-house line gives you the most controlled result — we own every variable from pre-treatment chemistry to final cure temperature. Up to 1,000hr salt spray.
Aluminum Parts
For aluminum parts needing both corrosion resistance and decorative finish, anodizing (Type II or Type III) is the standard approach. Managed through our partner network with full incoming QC.
Electrical / Conductive Parts
For steel or copper parts requiring electrical conductivity or precise decorative finishes, electroplating provides zinc, nickel, or chrome deposits to your specification.
Not sure? Our engineers recommend finishes during every DFM review.
From Fabrication to Finished Part
Surface finishing isn’t a bolt-on afterthought, it’s planned into your production from the first DFM review. Here’s how your parts move through our finishing workflow.
DFM & Specification
Coating type, color, thickness, test standards locked in before production begins.
Surface Preparation
7-stage pre-treatment: degreasing, acid clean, phosphating, DI rinse.
Finish Application
In-house powder coating or managed partner for plating, anodizing, e-coat.
Curing & Post-Treatment
Thermal cure for powder. Chemical sealing for anodize. Passivation for plating.
QC Inspection
Thickness, color (ΔE < 1.0), adhesion, salt spray, gloss — every batch.
Pack & Ship
Protective film, foam inserts, VCI paper. Ships direct to your receiving dock.
Surface Finishing Across Industries
Different industries demand different finish performance. Here’s how we match finishing solutions to specific industry requirements.
HVAC & Climate Control
Outdoor Durability
UV resistance, color matching across multi-unit installations. Carrier and Gree outdoor unit panels.
Powder Coating
Anti-rust
Automotive
OEM Standards
720+ hour salt spray, chip resistance. Honda and Xpeng structural brackets under IATF 16949.
E-Coating
Zinc Plating
Powder Coat
Electrical Enclosures
EMI & Corrosion
EMI shielding compatibility, RAL color specification. Control panels, server racks, outdoor cabinets.
Powder Coating
Zinc Plating
Consumer Appliances
Premium Appearance
Fingerprint resistance, scratch durability. Midea and Haier stainless steel panels and housings.
Brushing
Anti-fingerprint
Powder Coat
Industrial Equipment
Heavy-Duty Protection
Chemical resistance, industrial-grade durability. Machine housings, safety guards, tool cabinets.
Powder Coating
Electroplating
Energy & Outdoor
10+ Year Service Life
Extended UV, thermal cycling, weather resistance. Solar mounting, outdoor cabinets, energy storage.
Powder Coating
Anodizing
Surface Finished Parts We've Delivered
Check our recent works below.
Surface Finishing Design Guidelines
The decisions you make during design directly affect finish quality, cost, and lead time. These guidelines help you get better results from any surface finishing process.
1
Edge Radius
Maintain a minimum 0.5mm edge radius on parts for powder coating. Sharp edges attract excess powder buildup and can lead to thin spots or bare metal at corners.
2
Drain Holes & Hanging Points
Design drain holes into enclosed or tubular sections to allow pre-treatment chemicals to flow through and dry completely. Include hanging points or tooling holes for coating line fixturing.
3
Material-Finish Compatibility
Not every finish works with every metal. Anodizing requires aluminum. E-coating works on all conductive metals. Powder coating works on steel, aluminum, and most ferrous metals.
4
Masking for Selective Finishing
If your part has threads, mating surfaces, or grounding points that must remain uncoated, specify masking areas clearly on your drawing. We apply precision masking plugs and tape per your specification.
5
How to Specify Finishes
On your drawing or RFQ, specify: finish type, color (RAL number, Pantone code, or custom sample), thickness range, gloss level, and any test requirements. The more specific your callout, the more accurate your first sample.
6
Need the complete reference?
Our Surface Finishing Design Guide covers edge preparation, masking, material compatibility, and finish specification in detail.
Frequently Asked Questions
Everything you need to know about our surface finishing capabilities, process, and quality standards.
Still Have Questions?
Our engineering team provides finish recommendations as part of every DFM review, free of charge.
What surface finishes does ZAK offer?
We offer powder coating in-house on our 525m automated line, plus managed electroplating, anodizing (Type II and Type III), e-coating, brushing, polishing, and protective coatings through our vetted partner network. All finishes are quality-inspected at our facility before shipment.
What's the difference between in-house and managed finishing?
In-house means the finish is applied on our equipment, by our operators, in our Foshan facility. Managed means we coordinate the finish through a vetted partner facility, but parts pass through our incoming inspection lab before they ship to you. In both cases, you deal with one supplier, receive one quality report, and get one invoice.
What is the maximum part size for powder coating?
Our powder coating line handles parts up to 2,200 × 1,500 × 600mm. For larger parts or assemblies, contact our engineering team to discuss options.
Can you match a specific RAL or Pantone color?
Yes. We run the full RAL and Pantone color range, plus custom formulations matched to physical samples or color specifications. Our CR-400 colorimeter verifies ΔE < 1.0 batch-to-batch consistency. For ongoing production programs, we maintain color standards on file.
What salt spray performance can I expect?
Our in-house powder coating achieves up to 1,000 hours salt spray resistance per ASTM B117. This is achieved through our 7-stage pre-treatment process combined with powder selection and cure parameters. Managed finishes (e-coating, electroplating) can also achieve 500–1,000hr depending on specification.
Do you provide finishing for parts fabricated elsewhere?
Our surface finishing operation is primarily integrated with our fabrication programs. We don’t typically run finishing-only jobs for parts fabricated by other suppliers. If you need both fabrication and finishing, we can quote the complete program.
What certifications cover your finishing operations?
ISO 9001:2015 covers our quality management system across all production processes. IATF 16949:2016 covers automotive quality requirements including surface treatment operations. ISO 14001:2015 covers environmental management for coating waste and chemical handling.
Explore Our Full Manufacturing Capabilities
Sheet Metal Fabrication
Laser cutting, bending, welding, and assembly. Parts designed for finishing from the start.
Metal Stamping
Progressive die stamping for high-volume production. Integrated finishing available.
DFM Engineering
Design for manufacturability review including surface finish specification and optimization.
Quality & Certifications
ISO 9001, IATF 16949, ISO 14001. Full quality documentation and traceability.
Get Your Parts Finished Right
Tell us your finish requirements. Our engineers will review your design, recommend the optimal finish, and provide a complete fabrication + finishing quote.