DIN 50961 Fe/Zn 8 B specifies a minimum 8-micrometer thick, blue chromate-passivated electroplated zinc coating on iron or steel for moderate corrosion protection. This German standard is often used for fasteners, though it is frequently superseded by DIN EN ISO 2081 or RoHS-compliant alternatives. For a detailed breakdown of this specification, visit Scribd. DIN 50961 Electroplated ZN Coating | PDF - Scribd
DIN 50961 is replaced by DIN EN ISO 2081:2018. The equivalent designation for Fe Zn 8b is:
Testing and Quality Control: To ensure the quality of the coating, various tests are performed, including: din 50961 fe zn 8b
DIN 50961 Fe Zn 8b is a workhorse specification for light-duty, cost-sensitive, conductive zinc plating on steel. It is not for severe environments, but it excels in interior assemblies, electronics, and non-weather-exposed automotive parts.
Fe Zn 8b decodes as:
DIN 50961: The German standard for electroplated zinc coatings. Fe: The base material (Iron or Steel). Zn: The coating material (Zinc). 8: The minimum local thickness of the zinc layer (typically
Appearance: A brilliant blue surface with a metallic sheen and subtle rainbow iridescence. It is the most visually attractive of all chromate finishes. Corrosion Resistance (Red Rust): According to the standard, Fe Zn 8b must withstand 72 hours in the neutral salt spray test (NSS) before red rust appears (when using Cr(III) based passivations). Electrical Conductivity: The blue film is very thin (approx. 0.1–0.5 µm). Unlike yellow or olive passivations, Fe Zn 8b offers relatively low contact resistance, making it ideal for threaded connections that require electrical grounding (e.g., automotive chassis bolts, electronic enclosures). Weldability: Due to its thin, conductive layer, blue passivated zinc is preferred over thicker coatings for resistance spot welding. DIN 50961 Fe/Zn 8 B specifies a minimum
| Code | Treatment | Color | Corrosion resistance (Salt spray to red rust) | |------|-----------|-------|------------------------------------------------| | b | Blue passivation (thin, transparent) | Iridescent blue-clear | ~12-24 hours | | c | Yellow passivation (hexavalent Cr⁶⁺, historic) | Iridescent yellow | ~96-120 hours | | d | Thick-layer olive drab | Olive green | ~200+ hours | | e | Black passivation | Black | Variable |