) are used for precision fasteners with tight thread tolerances. 4. Chromate Conversion Coating / Passivation ( B )
: The German national standard that specifies terms, testing, and corrosion resistance for electroplated zinc coatings on iron or steel. It is typically used in conjunction with DIN EN ISO 2081. Fe : Indicates the substrate material is Iron or Steel . din 50961 fe zn 8b
Good for indoor or mild outdoor environments. ) are used for precision fasteners with tight
| Chromate Type | Appearance | Primary Characteristics | | :--- | :--- | :--- | | | Bluish, slightly iridescent | Typically contains hexavalent chromium (Cr⁶⁺) for moderate corrosion protection and a bright finish. Forms a thinner film than other types. | | C (Yellow) | Golden yellow, iridescent | Provides a thicker, heavier layer with significantly higher corrosion resistance than blue. | | D (Olive/Green) | Olive green | Very thick layer with maximum corrosion resistance. Often specified for the most severe environmental conditions. | | F (Black) | Matte to glossy black | Aesthetic black finish used for specialized applications such as automotive trim or firearms. | It is typically used in conjunction with DIN EN ISO 2081