Overview
EN ISO 2081:2025 - Metallic and other inorganic coatings - covers requirements for electroplated zinc coatings on iron and steel that are subsequently treated with chromium (VI) conversion solutions. Published by CEN and aligned with ISO 2081:2025, the standard specifies purchaser–electroplater information, coatings and supplementary treatment requirements, and heat‑treatment procedures before and after electroplating. It is intended for protective and decorative electroplated zinc finishes and supersedes EN ISO 2081:2018.
Key topics and technical requirements
- Scope and exclusions: Applies to electroplated zinc on fabricated iron/steel parts for protective/decorative use. Not applicable to sheet/strip/wire in non‑fabricated form, close‑coiled springs, or non‑protective uses.
- Purchaser information: Defines the essential and additional information purchasers must supply to the electroplater to ensure correct coating type and performance.
- Coating characteristics: Requirements for appearance, coating thickness, conversion coatings and supplementary treatments, and limitations for threaded components where dimensional fits restrict thickness.
- Adhesion and corrosion testing: Addresses adhesion of zinc and conversion coatings and accelerated corrosion testing (including neutral salt spray and corrosion rating methods).
- Heat treatments: Specifies stress‑relief heat treatments before cleaning/electroplating and hydrogen‑embrittlement‑relief heat treatments after electroplating.
- Sampling and measurement: Includes guidance on sampling and, via annex, measurement of average coating thickness on small articles.
- Safety and regulatory context: Notes health and environmental risks associated with hexavalent chromium and references regulatory constraints (e.g., REACH authorizations) and alternative systems.
Practical applications
EN ISO 2081:2025 is used to:
- Specify and procure electroplated zinc + chromium(VI) conversion coatings for corrosion protection and decorative finishes.
- Define inspection and test criteria (appearance, adhesion, salt spray performance) for quality control.
- Guide process decisions for heat treatment to mitigate hydrogen embrittlement on high‑strength steel parts.
- Inform acceptance criteria and contractual designation between manufacturers, electroplaters and purchasers.
Who uses this standard
- Electroplating shops and surface‑finish processors
- OEMs and component manufacturers in automotive, aerospace, machinery and fasteners industries
- Quality, procurement and standards compliance teams
- Testing laboratories and corrosion engineers
Related standards
- ISO 19598 - for trivalent chromium (Cr(III)) conversion coatings (chromium‑VI‑free alternatives)
- Previous edition: EN ISO 2081:2018 (superseded)
Keywords: EN ISO 2081:2025, electroplated zinc, chromium (VI), zinc coatings, electroplating, corrosion protection, neutral salt spray, hydrogen embrittlement.