Din 50961 Fe Zn 8b (DIRECT)
DIN 50961 Fe/Zn 8b
The code specifies a technical standard for electroplated zinc coatings on iron or steel. Code Breakdown
When is 8 µm sufficient?
Reality:
The "8" refers to the minimum local thickness on significant surfaces. Average thickness is typically higher (9–12 µm), and edges may be thicker due to current concentration. din 50961 fe zn 8b
- Low corrosion resistance compared to yellow or olive-drab.
- Hexavalent chromium concerns: Traditional type b passivation used Cr(VI), now banned in many jurisdictions (EU REACH, RoHS). Modern trivalent Cr(III) blue passivations are less robust.
- Not for high-strength fasteners unless baked: Risk of hydrogen embrittlement in steels > HRC 38.
- Poor wear resistance: Zinc is soft and can be damaged by friction.
DIN 50961 Fe/Zn 8b
Let's break down :
Top coat: none required – passivation type b suitable for organic adhesion. DIN 50961 Fe/Zn 8b The code specifies a
- Using a magnetic induction gauge (e.g., Fischerscope).
- Minimum local thickness: 8 µm on all significant surfaces.
- Edges and recesses may be thinner due to current distribution—acceptable per standard.