Din 50961: Fe Zn 8b ((new))

The designation DIN 50961 Fe/Zn 8b refers to a specific standard for electroplated zinc coatings on iron or steel. While this standard was technically replaced by DIN EN ISO 2081, it is still widely referenced in engineering specifications to define coating thickness and finish. Designation Breakdown

• Fe – Base material: Iron or steel.
• Zn – Coating metal: Zinc (electroplated).
• 8 – Coating thickness: Minimum 8 µm (micrometers).
• b – Post-treatment type: Blue or iridescent (yellow) chromating, typically trivalent chromium.

3. 8 (Thickness Class)

• Meaning: Nominal coating thickness = 8 micrometers (µm).
• Implication: DIN 50961 defines thickness classes from 1 to 25 µm. Class 8 requires a minimum local thickness of 8 µm. In practice, the average thickness may range from 8 to 12 µm, depending on the part geometry and bath chemistry.

Important Warning: Historically, "b" passivation used hexavalent chromium (Cr VI). Due to EU RoHS and ELV directives, most modern Fe Zn 8b coatings use trivalent chromium (Cr III). The corrosion resistance is similar, but the color is slightly less iridescent. Always clarify with your plater if hex-free is mandatory. din 50961 fe zn 8b

). This thickness is standard for "moderate" indoor environments. The designation DIN 50961 Fe/Zn 8b refers to

Conversion Table: