Cr6+ vs Cr3+
Old chromates used hexavalent chromium (Cr6)—great protection but toxic and carcinogenic, hence restricted under RoHS/REACH.
Trivalent (Cr3+) chromate uses a safer form of chromium, giving comparable protection while meeting environmental rules.
Why it matters
Parts exported to the EU/Japan, or feeding automotive/electronics supply chains, usually mandate Cr6-free.
Using Cr6 can mean a whole lot rejected or a customer lost—choosing Cr3+ up front is safer.
Our plating
We zinc-plate with a trivalent (Cr3+) chromate system, Cr6-free and RoHS-ready.
We can issue process confirmation and salt-spray test results with your order on request.
FAQ
Does Cr3+ match Cr6 for corrosion?+
A good Cr3+ system (with a sealer) matches or approaches Cr6 in many jobs and can pass salt spray to spec.
Do you provide RoHS documentation?+
Yes—Cr6-free process confirmation plus corrosion test results to attach to your job.
Is Cr3+ required for domestic work?+
Not always, but it is recommended—safer and future-proof for export.
Free Engineering Tools
- Hardness Converter HRC ↔ HV ↔ HB
- Which Steel Grades Harden — and How Far
- Fastener Weight: pcs ↔ kg
- Finishing Specification Builder for Purchasing and QC
- Salt Spray Test Plan Builder
- Coating thickness → thread fit (GO/NO-GO)
- Hydrogen Embrittlement — is baking required?
- Bolt Tightening Torque & Proof Load
- Thread Engagement Length
- Bolt Size Estimator (from load)
- Bolt Property Class — Mechanical Properties (ISO 898-1)
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Technical content review
Reviewed by the V.S. Heat Treatment QA and production team—heat-treatment and finishing operations since 1994 under an ISO 9001:2015 quality system.
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