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.