Black Epoxy Coated N52 Industrial Rare Earth Permanent Magnet With 20 mm Diameter

1. Ring Magnet Information

What are neodymium magnets? Are they the same as "rare earth"?

Neodymium magnets are a member of the rare earth magnet family. They are called "rare earth" because neodymium is a member of the "rare earth" elements on the periodic table. Neodymium magnets are the strongest of the rare earth magnets and are the strongest permanent magnets in the world.

What are neodymium magnets made from and how are they made?

Neodymium magnets are actually composed of neodymium, iron and boron (they are also referred to as NIB or NdFeB magnets).  The powdered mixture is pressed under great pressure into molds.  The material is then sintered (heated under a vacuum), cooled, and then ground or sliced into the desired shape.  Coatings are then applied if required.  Finally, the blank magnets are magnetized by exposing them to a very powerful magnetic field in excess of 30 KOe.

How is the strength of a magnet measured?

Gaussmeters are used to measure the magnetic field density at the surface of the magnet. This is referred to as the surface field and is measured in Gauss (or Tesla).  Pull Force Testers are used to test the holding force of a magnet that is in contact with a flat steel plate. Pull forces are measured in pounds (or kilograms).

What does the "N rating", or grade, of the neodymium magnets mean?

The grade, or "N rating" of the magnet refers to the Maximum Energy Product of the material that the magnet is made from.  It refers to the maximum strength that the material can be magnetized to.  The grade of neodymium magnets is generally measured in units millions of Gauss Oersted (MGOe).  A magnet of grade N42 has a Maximum Energy Product of 42 MGOe.  Generally speaking, the higher the grade, the stronger the magnet.

2.  What is the difference between the different platings and coatings?

  Choosing different coatings does not affect the magnetic strength or performance of the magnet, except for our Plastic and Rubber Coated Magnets.  The preferred coating is dictated by preference or intended application.  More detailed specifications can be found on our Specs page.

♦ Nickel is the most common choice for plating neodymium magnets. It is actually a triple  plating of nickel-copper-  

   nickel. It has a shiny silver finish and has good resistance to corrosion in many applications. It is not waterproof.

♦ Black nickel has a shiny appearance in a charcoal or gunmetal color. A black dye is added to the final nickel plating 

    process of the triple plating of nickelcopperblack nickel.

    NOTE: It does not appear completely black like epoxy coatings. It is also still shiny, much like plain nickel plated magnets.

♦Zinc has a dull gray/bluish finish, that is more susceptible to corrosion than nickel. Zinc can leave a black residue on

   hands and other items.

♦ Epoxy is basically a plastic coating that is more corrosion resistant as long as the coating is intact. It is easily scratched. 

   From our experience, it is the least durable of the available coatings.

♦ Gold plating is applied over the top of standard nickel plating. Gold plated magnets have the same characteristics as 

   nickel plated ones, but with a gold finish

3. Specification About Ring Magnet

4. Ring Magnetize Direction

5. Other Available Products

6. Our Service

  Ningbo Jinyu magnet Co.,Ltd locates in Ningbo,Zhejing province ,established in 1996.

  It is a high-tech enterprise and specialized in studying and resarch and applying NdFeB rare-earth permanent magnets.

  All the permanent magnets achieved the standard SGS ISO9001,and RoHS.We have series of proprietary technology and complete localizationof equipment sys