Trivalent Chrome Passivation (SurTec 650) is now available for aluminium surface treatment in meviy
Trivalent Chromate Passivation (SurTec 650) is now available as a surface treatment option in meviy’s sheet metal fabrication service. This chromium (VI)-free technology provides excellent corrosion resistance, low electrical contact resistance, and strong adhesion properties for aluminium parts.
Already approved by OEMs (Original Equipment Manufacturer) across aerospace, e-mobility, and electronics, Trivalent chromate passivation (SurTec 650) is fully compliant with REACH, RoHS, and MIL-DTL standards, and is officially QPL listed. It offers a premium and sustainable alternative to traditional Cr (VI) coatings without compromising performance.
You can now select Trivalent Chromate Passivation (SurTec 650) directly in the specification screen after uploading your CAD model, alongside your chosen material and surface finish.
What is Trivalent Chromate Passivation (SurTec 650)?
The treatment forms a thin, stable, and inert oxide layer that provides excellent corrosion resistance while maintaining electrical conductivity. The resulting surface is typically colourless to slightly iridescent and supports strong adhesion for paints, adhesives, and sealing compounds.
Trivalent Chromate Passivation (SurTec 650) is approved to MIL-DTL-81706B (Classes 1A and 3) and MIL-DTL-5541F, is QPL listed, and fully complies with REACH and RoHS directives. It is widely used in industries where electrical performance, surface stability, and regulatory compliance are critical.
Typical performance characteristics:
- Contact resistance below 5000 µΩ/in²
- Corrosion resistance up to 500 hours (neutral salt spray, depending on alloy)
- Compatibility with bonding, coating, and EMC applications
- Prevention of moisture ingress in gasketed or sealed assemblies
Thanks of its combination of durability, conductivity, and environmental safety, it has become a standard for surface treatment in aerospace, automotive, electronics, and telecommunications.
Technical specifications:
| Property | Specification |
|---|---|
| Surface type | Chemical conversion coating based on trivalent chromium (Cr (III)) |
| Substrate compatibility | Aluminium and aluminium alloys |
| Corrosion resistance | Up to 500 hours (neutral salt spray, depending on alloy) |
| Electrical contact resistance | Less than 5000 µΩ/in² |
| Appearance | Colourless to slightly iridescent |
| Standards | MIL-DTL-81706B (Classes 1A and 3), MIL-DTL-5541F |
| Certifications | QPL listed, REACH and RoHS compliant |
| Paint and bonding compatibility | Compatible with Cr-free primers, adhesives, sealants |
| Typical layer thickness | Approx. 0.2–0.5 μm |
Key Features:
Feature | Benefit |
|---|---|
| Chromium (VI)-free | Environmentally safe and REACH compliant |
| Corrosion protection | Up to 500 h NSS – protects bare aluminium surfaces |
| Electrical conductivity | Maintains low, stable contact resistance |
| Paint & adhesive readiness | Strong bonding with coatings, adhesives, and sealants |
| Seal integrity support | Prevents seal creep in gasketed components |
| EMC compatibility | Ideal for shielding and grounding applications |
| Process stability | Consistent performance across various aluminum alloys |
| Standards compliance | MIL-DTL and QPL certified for regulated industries |
Applications of Trivalent Chromate Passivation (SurTec 650) Across Industries
Trivalent Chromate Passivation (SurTec 650) is used across sectors where a combination of corrosion protection, electrical conductivity, and regulatory compliance is essential. Its compatibility with downstream processes such as painting, bonding, and sealing makes it highly versatile for both functional and structural applications.
Aerospace
- Structural components made from aluminum
- Avionics housings requiring low contact resistance
- Fasteners and brackets exposed to harsh environments
- Lightweight parts requiring MIL-DTL compliance
E-Mobility and Automotive
- ECU housings and enclosures for battery management systems
- Aluminium brackets and structural supports with grounding requirements
- Contact-sensitive parts requiring seal creep protection
- Body-in-white components requiring paint adhesion
Electronics and Electrical Engineering
- Aluminium housings for shielding-sensitive devices
- Connectors and enclosures requiring stable surface conductivity
- Components exposed to temperature fluctuations and humidity
5G and Telecommunications
- Antenna enclosures and mounts requiring environmental resistance
- Signal boxes and grounding plates in outdoor infrastructure
- Passive equipment housings where contact corrosion must be prevented
This broad usability across industries makes Trivalent Chromate Passivation (SurTec 650) a preferred standard for OEMs and Tier suppliers working with precision aluminium parts.
Why Choose Trivalent Chromate Passivation (SurTec 650) on meviy?
Choosing Trivalent Chromate Passivation (SurTec 650) via meviy gives you access to certified surface treatment with the efficiency of digital manufacturing. It offers proven performance alongside instant pricing, rapid lead times, and seamless integration into your design and procurement workflow.
By combining this high-performance surface treatment with meviy’s automated sheet metal service, engineers and procurement teams save time without compromising technical standards or compliance requirements.
Summary
Trivalent Chromate Passivation (SurTec 650) offers a powerful combination of performance, compliance, and sustainability for aluminium parts. As a chromium (VI)-free surface treatment, it meets the highest international standards for corrosion protection, electrical conductivity, and paint or adhesive bonding — making it the ideal solution for industries such as aerospace, e-mobility, electronics, and telecommunications.
Fully REACH and RoHS compliant, QPL listed, and MIL-DTL certified, Trivalent Chromate Passivation (SurTec 650) is trusted by leading OEMs and Tier suppliers for both prototypes and series production. It supports modern manufacturing processes by delivering consistent quality, surface stability, and downstream compatibility.
Available now in meviy’s sheet metal fabrication service, this treatment can be selected easily after CAD upload. Engineers and procurement teams benefit from instant quoting, fast lead times, and complete regulatory confidence.
Eco-compliant. Electrically superior. Universally trusted.
What is meviy?
meviy is an AI-powered on-demand manufacturing platform developed by MISUMI. Engineers can upload 3D CAD models to receive instant pricing, manufacturability feedback, and lead time estimates. Supporting processes like CNC milling, sheet metal fabrication and CNC turning, meviy streamlines procurement, reduces communication loops, and accelerates product development. Its AI capabilities also enable part recognition, interactive design editing, and compatibility with a wide range of materials, making it a smart, fast, and reliable tool for today’s engineering teams.
