What is electro galvanizing meaning?

Electro galvanizing refers to the process of depositing a zinc coating on steel parts using an electric current in an electrolyte bath. It is also known as electroplated zinc. The coating provides corrosion protection and is specified by standards such as ISO 2081 / GB/T 9799, with performance depending on the application conditions.

What is the difference between electro galvanizing vs electroplating?

Electro galvanizing vs electroplating: electro galvanizing is a specific type of electroplating where zinc is the coating metal. Electroplating is a broader term that includes other metals like nickel, chromium, etc. So electro galvanizing is a subset of electroplating.

What is the electro galvanizing standard?

The electro galvanizing standard is ISO 2081 (current version: BS EN ISO 2081:2018; new edition: ISO 2081:2025) and GB/T 9799-2024 (identical to ISO 2081). These standards specify coating designation, thickness classes, and supplementary treatment requirements. The specific thickness class depends on application conditions and must be applied as specified by the standard.

How is electro galvanizing thickness specified?

Electro galvanizing thickness is specified by standard classes in the designation format Fe/Zn + minimum thickness in µm + conversion coating code (e.g., Fe/Zn25/X). The thickness on threaded parts is limited by thread class or assembly requirements. For salt spray correlation, see our whitepaper.

What equipment is used in an electro galvanizing plant?

An electro galvanizing plant uses electro galvanizing equipment including plating tanks, rectifiers, filtration systems, and an electro-galvanizing line (automated or manual). Production is handled by our partner electro galvanizing plant on an automated line, and our on-site QC team inspects each batch for consistent quality.

ISO 2081 / GB/T 9799 compliant · Trivalent chromium passivation (performance depends on application conditions)

Electro Galvanizing: Uniform Zinc Coating for Corrosion Protection

Electro galvanizing (electroplated zinc) provides a uniform, tightly adherent coating on steel fasteners and parts. Processed per ISO 2081 / GB/T 9799, with trivalent chromium conversion coatings. Thickness is specified by standard classes, depending on the application conditions and required corrosion protection, including options for elevated temperatures.

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Electro Galvanizing: Uniform Zinc Coating for Corrosion Protection

Process Overview

How It Works

Electro galvanizing (also referred to as electrodeposited zinc) deposits a uniform zinc layer onto steel components via an electrolytic cell. In this process, parts are immersed in a zinc electrolyte bath and connected to a direct current source within an electroplating line. Zinc ions are reduced at the steel surface, forming a coating thickness as specified by the applicable standard, with uniformity dependent on application conditions. Performance at elevated temperatures must be evaluated in conjunction with the specific service environment.

Key Advantages

✓Uniform coating thickness across complex geometries, including threads and recesses
✓Precise thickness control per standard classes (e.g., Fe/Zn25/X)
✓Trivalent chromium conversion coatings replace hexavalent chromium, as specified by the applicable standard.
✓Hydrogen embrittlement relief heat treatment available per standard, with parameters depending on application conditions and elevated temperatures.
✓Cost-effective for high-volume fastener production

Typical Applications

Electro galvanizing is widely used for fasteners (bolts, nuts, screws), automotive components, electrical enclosures, and general industrial parts requiring corrosion protection with tight dimensional tolerances. It is a preferred choice for indoor and moderate outdoor exposure.

Capability Envelope

Standards	ISO 2081 (BS EN ISO 2081:2018 current; ISO 2081:2025 new version) / GB/T 9799-2024 (identical to ISO 2081)
Designation	Fe/Zn + minimum thickness in µm + conversion coating code (e.g., Fe/Zn12/C, Fe/Zn25/X)
Thickness	Specified by standard classes (e.g., Fe/Zn25/X); thickness on threaded parts limited by thread class or assembly requirements
Conversion coating	Trivalent chromium (replaces hexavalent per ISO 2081:2018 update, with performance requirements depending on application conditions and elevated temperature exposure)
Hydrogen embrittlement relief	Post-plate heat treatment (e.g., at elevated temperatures for a duration per standard) when specified.
SKU volume	658 zinc plated SKUs in live catalog
Diameter range	M3 to M30 (M16 93, M12 93, M20 87, M10 85, M8 80, M24 57, M6 53, M30 43, M5 34, M4 21, M3 12)
Grade distribution	8.8 (597 SKUs), 4.8 (25), 8 (11), 10.9 (1); anchor-bolt family additionally 4.6/8.8 (Q235/45#)

Our partner electro galvanizing plant runs an automated electro-galvanizing line, and our on-site QC team inspects each production batch. We offer electro galvanizing services for fasteners and custom parts. For coating thickness vs. salt spray hours data, refer to our whitepaper. For inquiries from electro galvanizing companies in UAE or elsewhere, contact us.

Per ISO 2081 / GB/T 9799 (electroplated zinc coatings; Fe/Zn designation; performance criteria per standard specification, dependent on application conditions, including elevated temperatures)

Design & Cost Tips (DFM)

Specify thread class before plating

Plating adds thickness to threads. Use 6g/6H classes and allow for coating buildup on critical fits.

Blind holes need drainage

Trapped solution causes spotting and uneven coating. Provide venting or through-holes where possible.

Avoid sharp edges and burrs

Sharp edges can lead to increased coating thickness and potential edge flaking. Chamfering should be performed as specified by the standard, with the chamfer radius depending on application conditions. Special attention is required under elevated temperatures.

Mask precision surfaces

Plating adds microns to dimensions. Mask bores, threads, or mating faces that must stay tight.

High-strength steel needs baking

Above certain hardness, hydrogen embrittlement relief is mandatory. Plan for post-plate baking.

Batch sizing and cost efficiency

Material, machine time, finishing, and inspection are all quoted per batch.

Selection Boundaries: When to Use, When Not

Good fit

✓Fasteners requiring uniform coating on threads (bolts, nuts, screws)
✓Parts with tight dimensional tolerances where coating thickness must be controlled
✓Indoor or moderate outdoor exposure where a thin, decorative zinc coating is sufficient
✓Applications requiring trivalent chromium passivation (environmental compliance)

Not recommended

✗Severe outdoor or marine environments: hot-dip galvanizing or stainless steel is recommended
✗Parts with very high corrosion resistance requirements (see our blog on greenhouse and coastal solar applications)
✗High-temperature applications (zinc coating may degrade)
✗Large structural parts where thicker coatings are needed