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Which magnet coatings are there?

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    Which magnet coatings are there?
    Update Time:2019-04-02
    Table of Contents
    Neodymium magnets (super magnets): Coating necessary
    Nickel (Ni-Cu-Ni)
    Gold-coating (Ni-Cu-Ni-Au)
    Chrome (Ni-Cu-Ni-Cr)
    Copper (Ni-Cu)
    Epoxy resin (Ni-Cu-Ni-Epoxy)
    Zinc (Zn)
    Pot magnets
    Special coatings
    Ferrite magnets: No coating
    Neodymium magnets (super magnets): Coating necessary
    Neodymium reacts to oxygen and oxidises quickly if untreated. That's why all neodymium magnets in our shop are covered with a protective coating, which is so thin that it doesn't have any impact on the adhesive force of the magnet.
    We use the following coatings on our neodymium magnets:
    Nickel (Ni-Cu-Ni)
    By far the most frequently used coating
    Colour: shiny metallic
    Good price/performance ratio
    Thickness: approx. 12 micro metres
    Gold-coating (Ni-Cu-Ni-Au)
    Razor-thin coating (24k) over normal Ni-Cu-Ni coat, but with the same features
    Colour: shiny metallic
    Thickness of gold-coating without Ni-Cu-Ni: 0,05 micro metre
    Thickness of whole coating: approx. 12 micro metres
    The gold-coating rubs off easily with frequent use. It is therefore suitable for decorative purposes only, not for playing or working.
    Chrome (Ni-Cu-Ni-Cr)
    Better resistance against rubbing and pressure (that's why we use this coating for our sphere magnets)
    Colour: dull, grey-metallic
    Thickness: approx. 15 micro metres
    Copper (Ni-Cu)
    Colour: shiny brown-red-gold. The colour may change over time due to oxidation (darkening, spots)!
    Slightly weaker rubbing and impact resistance than Ni-Cu-Ni
    Slightly weaker corrosion resistance than als Ni-Cu-Ni
    Thickness: approx. 10 micro metres
    The copper-coloured surface rubs off with frequent use (similar to gold-coated magnets) and is therefore suitable for decorative purposes only.
    Epoxy resin (Ni-Cu-Ni-Epoxy)
    (in exceptional cases also just epoxy)
    Colour: black
    almost 100% non-corrosive, as long as coating is intact
    not shock-resistant (crumbles quickly)
    Thickness: approx. 10 micrometre
    Even the smallest, not visible to the eye, damages of the coating will cause damage to the magnet in the long term when exposed to moisture.
    Zinc (Zn)
    Colour: matt grey/blueish
    only zinc without Ni-Cu-Ni
    more susceptible to corrosion than Ni-Cu-Ni
    can leave black marks
    Thickness: approx. 4 micrometres
    Pot magnets
    If not noted otherwise, we use neodymium magnets with a Ni-Cu-Ni coating for our pot magnets. The term "coating" in the article description of pot magnets refers to the steel pot around the magnet. In most cases it is nickel (Ni); for the pot magnets that are painted white it is nickel with additional powder coating.
    Special coatings
    There is a variety of other coatings for neodymium magnets that we do not (or only sporadically) offer in our standard assortment.
    Without coating
    Naked magnet material, black/grey
    Magnets oxidise and corrode quickly when they come in contact with oxygen and water
    Magnets need to be covered air- and watertight quickly
    We do not recommend having uncoated magnets manufactured.
    Silver (Ni-Cu-Ni-Ag)
    Shiny silver
    Razor-thin coating over normal Ni-Cu-Ni coating, hence the same attributes
    Difference purely visual
    Material: Sterling Silver
    Approx. 12 micrometres thick
    Teflon
    Grey/anthracite
    Only teflon without Ni-Cu-Ni
    Nearly waterproof
    Very rub-resistant
    12-25 micrometres thick
    Ferrite magnets: No coating
    In theory, you could put various coats on ferrite magnets, but that is technically complex and expensive. The price for the coating would be greater than the price for the whole magnet.
    Since ferrite magnets are weather-resistant even without protection, an additional coating is not necessary. Our ferrite magnets are therefore uncoated.