NdFeB Magnets react to oxygen and oxidize quickly if untreated. In order to maximize corrosion stability for longer service, NdFeB magnets require additional protection against corrosion.
All NdFeB Magnets supplied by Stanford Magnets are covered with a protective coating, which is so thin that it will not have any effect on the adhesive of the magnet. The coating meets the requirements for minimal coating thickness, good adhesion, resistance to weathering influence, excellent temperature stability, and reliability of the coating process at high temperatures.
We use the following coatings on our Neodymium Magnets:
By far the most frequently used coating; Colour: shiny metallic; Good price/performance ratio; Thickness: approx. 12 micrometres.
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 micrometres; The gold-coating rubs off easily with frequent use. It is therefore suitable for decorative purposes only, not for playing or working.
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
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 also Ni-Cu-Ni Thickness: approx. 10 micro metres
Epoxy resin (Ni-Cu-Ni-Epoxy)
Colour: black almost 100% non-corrosive, as long as the coating is intact not shock-resistant (crumbles quickly) Thickness: approx. 10 micrometre Even the smallest, not visible to the eye, damages the coating and will cause damage to the magnet in the long term when exposed to moisture.
0.08" thickness or more; White Color. The raw materials of Teflon are from DuPont and approved by the test (FDA method) of Daikin Industries. Good chemical stability and corrosion resistance are frequently used in dental and medical applications
0.04" thickness; various colors highly corrosion resistant, increased friction
Neodymium Magnets Coating Necessity
Neodymium reacts to oxygen and oxidizes 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.
Othert neodymium magnets coatings we offer:
Stanford Magnets has been providing various neodymium magnets coatings for over 10 years.
Nickel Coated Magnets
Black Nickel Coated Magnets
Cr3+Zinc Coated Magnets
Zinc Coated Magnets
Gold Coated Magnets
Silver Coated Magnets
Epoxy Coated Magnets
Passivation Coated Magnets
Phosphated Coated Magnets
Plastic Coated Magnets
Rubber Coated Magnets
Magnets Requiring no Protective Coating
Teflon (PTFE) Coated Magnets
Salt Spray Test
Pressure Cooker Test
NiCuNi (Nickel Copper Nickel)
NiCu + Black Nickel
NiCuNi + Epoxy
NiCuNi + Gold
NiCuNi + Silver
Each individual layer of Nickel and Copper are 5-7 μm thick. The Gold and Silver plating layers are 1-2 μm thick.
Test results shown to allow comparison between plating options. Performance in your application under your specific test conditions may vary. Salt Spray testing conducted with a 5% NaCl solution, at 35°C. Pressure Cooker Test (PCT) conducted at 2 atm, 120°C at 100% RH.
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