Zinc flake coating
Zinc flake coatings are non-electrolytically applied coatings, which provide good protection against corrosion. These coatings consist of a mixture of zinc and aluminium flakes, which are bonded together by an inorganic matrix.
The specifications for zinc flake coatings are defined in international standard ISO 10683 and also in European standard EN 13858. ISO 10683 sets out the requirements for zinc flake coatings for threaded fasteners and EN 13858 describes the requirements for zinc flake coatings for fasteners with no thread and for other parts as well.
Today, these are the preferred coatings for fasteners and other parts in the automotive industry, as they offer various advantages:
Good appearance (colouring)
Very good protection against corrosion (240 - 1,500 hours, depending on specification and coating thickness)
Resistant to extreme temperatures
Good chemical resistance