High-current density areas (outer edges, threads, sharp corners) typically receive thicker layers.
| Requirement | Does Fe Zn 8b meet it? | |-------------|-------------------------| | Low cost | ✅ Yes | | Conductive (grounding) | ✅ Yes (type b) | | Indoor corrosion protection | ✅ Yes (5–10 years) | | Outdoor/salt exposure | ❌ No – use 8c or 12d | | Hexavalent chromium free | ⚠️ Only if specified tCr(III) | | High-strength steel (>1200 MPa) | ⚠️ Only with mandatory baking |
Historically, this included hexavalent chromium, but under current environmental regulations (RoHS/REACH), this has largely transitioned to trivalent chromium (Cr3+), which is more environmentally friendly and often performs better in corrosion resistance tests. Typical Characteristics Appearance: Bright blue-ish or transparent/matte look.
For technical drawings requiring global interpretation, consider adding an identical ISO 2081 callout (e.g., ISO 2081 Fe/Zn 8b ), but if your supply chain is German or Central European, remains the gold standard for clear, unambiguous zinc plating specifications. din 50961 fe zn 8b
What is the of your steel? Will the parts be used indoors or outdoors ?
Raw zinc oxidizes quickly, forming "white rust." Applying a chromate conversion layer chemically seals the zinc, significantly delaying this oxidation.
: Denotes the passivation or chromate treatment type . In the DIN 50961 system, "b" (sometimes interchanged with "B") typically refers to blue or clear chromating , which provides a transparent, often slightly iridescent finish. Why Use DIN 50961 Fe Zn 8b? Will the parts be used indoors or outdoors
When sourcing, ensure that the supplier provides RoHS-compliant trivalent passivation to meet current environmental regulations, and always consider the 8 μ m thickness when designing threaded fasteners.
The shorthand is a layered code. Here is the exact breakdown of each character:
The letters immediately following the slash indicate the sacrificial coating layer. stands for Zinc. This means the layer is applied via electroplating (galvanic deposition) rather than hot-dip galvanizing or mechanical plating. 3. 8 (Coating Thickness) In this case
A specification is only as good as its testing regime. For DIN 50961 Fe/Zn 8B to be valid, the coatings must pass rigorous standardized tests.
The European standard equivalent for clear/blue-bright electroplated zinc.
: Denotes the minimum local coating thickness in micrometers (μ m). In this case, 8 μ m.
"Fe" stands for Ferrum , the Latin word for iron. This denotes that the underlying material (the substrate) being plated must be iron or steel. 3. Zn (The Coating Metal)
The longevity of a zinc coating is directly proportional to its thickness and the efficacy of its passivation layer. Salt Spray Test Performance