POPULAR COATINGS | COATING APPLICATION CHART | OTHER COATINGS

By their nature, Neodymium magnets are a brittle material that require coatings to help protect against breakage, scratches or corrosion. That’s why, at FIRST4MAGNETS® we supply all our Neodymium magnets already triple-coated (unless specifically requested otherwise). The typical coating for a Neodymium magnet is a layer of nickel followed by a layer of copper and then nickel again. However, there are many different coatings used on our magnets including gold, rubber, Polytetrafluoroethylene (PTFE) and more. These coatings are all designed to fit a variety of applications and have a wide range of benefits to suit your requirements.

Good to know- During manufacture, all our magnets are thoroughly dried to prevent moisture being captured underneath the coating during the coating and plating process. 

Popular Coatings

Nickel (Ni-Cu-Ni)

  • This coating is available on all our Neodymium magnets.
  • Provides protection against corrosion of the magnet in outdoor situations.
  • Maximum working temperature is approximately 220-240ºC (depending on the max working temp of magnet).
  • Suitable applications: engines, generators, sensors, automotive applications, retention, and pumps.

 

 

Rubber

  • This coating is available on a range of our Neodymium magnets.
  • Protects against breakages, impacts & minimizes corrosion.
  • The rubber coating provides good slip resistance on steel surfaces, great for fixing signage or artwork in a sheer position.
  • Maximum working temperature is around 80-100°C.

Epoxy

  • This coating is available on some of our Neodymium magnets.
  • Provides an excellent barrier against water and corrosive fluids.
  • Maximum working temperature is approximately 150°C.
  • Suitable applications: Engines, sensors, consumer goods and automotive applications.

Gold (Au)

  • This coating is available on a selection of Neodymium magnets. Under the gold coating there is a sub-layer of Ni-Cu-Ni.
  • Maximum working temperature is around 200°C.
  • Suitable applications: Therapy magnets, jewellery, or decorative purposes.

Zinc (Zn)

  • This coating is available on a selection of zinc plated Neodymium magnets.
  • Maximum working temperature is less than 120°C.
  • Protects against corrosion in the open air.
  • Suitable for low temperature applications.

Polytetrafluoroethylene (PTFE)

  • This coating is available on a selection of Neodymium magnets.
  • Maximum working temperature is up to 250°C.
  • Provides protection against impacts, corrosion and moisture.
  • Suitable for Fixtures and fixings, medical and food industries.

Chrome

  • This coating is available on a range of our Neodymium pot magnets.
  • Maximum working temperature is around 200°C.
  • Suitable applications: Fixtures and fixings, magnet fishing, or decorative purposes.

Good to know- A Neodymium magnet kept in dry conditions – not subjected to excessive heat, radiation or strong external magnetic fields will not corrode and will retain its magnetic output for many, many years. Permanent magnets lose their magnetism at a rate of approximately 5% every 100 years, meaning they aren’t actually ‘permanent’ in the truest sense of the word, but when handled with care, in the right conditions Neodymium magnets will maintain their magnetism for a very long time.

Need help on what coating you need?

Here we have put together a comparison chart to help you decide what coating is best suited for your application. 

 

Ni-Cu-Ni

Rubber

Epoxy

Au

Zn

PTFE

Chrome

Indoor Applications

Outdoor Applications

High Temperature Applications

220-240ºC*
(*depending on 
the max working
temp of magnet)

80-100ºC or less

150ºC or less

Up to 200ºC

120ºC or less

Up to 250ºC

Up to 200ºC

Low Temperature Applications

220-240ºC* 

80-100ºC or less

150ºC or less

Up to 200ºC

120ºC or less

Up to 250ºC

Up to 200ºC

Water Applications

 

Other Coating Options

The below coatings are most commonly used with Neodymium magnets, designed with specific applications in mind.

Tin (Sn)

Tin plating/coating creates resistance against corrosion, ductility, and solderability. Due to its low transfer resistance means they are commonly used in electrics and electronic industries. 

Titanium (Ti)

This is a coating that when applied creates resistance to corrosion in sea water, aqua regia, and chlorine.

Titanium Nitride (TiN)  

This is a coating that when applied creates resistance against most chemicals. This coating is commonly used for medicine applications due to its high corrosion resistance and being non-reactive within human bodies. Maximum working temperature is approximately 500 ° C.

Parylene C 

This coating provides protection from moisture, corrosive bodily fluids, chemicals, temperature and fungus. As such, they are most commonly used within medical and technology applications. Parylene coated magnets can also be suitable for outdoor applications, where the maximum working temperature is approximately 150°C.

Everlube®

Everlube® created a range of tough coatings, to suit a variety of needs. Magnets can be coated in this to help protect against chemical corrosion, high temperatures and rust.

 

Nickel-Copper-Nickel – Plus Rubber

These coatings have the same advantages of Nickel-Copper-Nickel coating, such as protection against corrosion, but with rubber added it also creates good slip resistance. Ideal for using on applications steel surfaces.

Zinc – Plus Rubber

This coating benefits from working in low temperatures thanks to the zinc element, and when partnered with rubber, allows for the magnet to be slip resistant. Ideal for using on applications on steel surfaces or within water or low temperature applications.

Nickel-Copper-Nickel – Plus Parylene

These coatings boast the same advantages of Nickel-Copper-Nickel coating, but by adding Parylene, this supports the magnet further for electrical applications.

Nickel-Copper-Nickel – Plus PTFE

These coatings boast the same advantages of Nickel-Copper-Nickel coating, but by adding PTFE creates an added protective coating against impacts and breakages. 

Tin – Plus Parylene

Both Tin and Parylene can be used within electric circuits and electrical insulation. When they are combined together, they create the perfect combination whilst aligning both of their benefits together.

Phosphate passivation

Phosphate coating provides strong adhesion and corrosion protection and also improves the friction properties of sliding components.

For help and advice on choosing the right coating for your application call our technical experts today on 

0845 519 4701 | sales@first4magnets.com

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