Some basic knowledge of magnets

- Apr 10, 2018 -

Magnets are objects or materials that can produce magnetic fields, which are traditionally classified as "permanent and permanent magnets, rare earth permanent magnets, NdFeB permanent magnets, NdFeB strong magnets" and "non immortal Magnets".

The permanent magnet can be natural products, also called natural magnets, and can also be made by hand (the strongest magnet is neodymium magnet). Rather than immortal magnets, they lose magnetism.

Fundamental knowledge

The ancient Greeks and Chinese discovered a natural magnetic stone in nature, which is called "magnet". This stone can suck small pieces of iron like tricks, and always point to the same deviation when swinging freely. The early navigators used this magnet as their earliest compass to distinguish the deviation from the sea.

After thousands of years of growth, today's magnet has become a powerful material in our life. After decomposition of alloys of different materials can be achieved with the same magnet effect, and can improve the magnetic force. In eighteenth Century, artificial magnets appeared, but the process of making stronger magnetic materials was very slow. Until 1920s, Alnico was produced. Subsequently, in 1950s, ferrite (Ferrite) was made in 1950s, and rare earth magnet was made in 70s, including neodymium iron boron (NdFeB) and SM CO (SmCo)]. So far, magnetic technology has been growing rapidly, and strong magnetic materials also make components smaller.

Magnetization (orientation) bias

A large number of magnetic materials can be magnetized to saturation along the same bias. This bias is called magnetization bias (orientation bias). The magnets without orientation bias (also known as isotropic magnets) are much weaker than the orientational magnets (also called anisotropic magnets).

What is the standard "north and South Pole" industry definition?

The definition of "Arctic" is that when the magnet is spinning at random, its north pole points to the north pole of the earth.  Similarly, the Antarctic pole of the magnet also points to the south pole of the earth.

How to distinguish the north pole of magnet in the absence of annotation?

It is obvious that the eyes are not discernible. The compass can be used close to the magnet, and the pointer to the earth's North Pole will point to the south pole of the magnet.

How to handle and deposit magnets quietly?

Always be very careful, because the magnet will absorb itself together, and it will probably hurt your fingers. When magnets adsorb on each other, they may also damage the magnet itself due to collision.

Keep magnets away from magnetized items, such as floppy disks, credit cards, computer monitors, watches, cell phones, medical things, etc.

The magnet should be far away from the cardiac pacemaker.

Larger size magnets, plastic or hard paper gaskets should be added between each piece to ensure that the magnet can be easily left.

Magnets should be kept in a dry and constant environment.

How do you do magnetic isolation?

As long as the material that can be adsorbed on the magnet can play the role of isolating the magnetic field, and the thicker the material is, the better the effect of magnetic separation is.

Now the highest functional magnet is rare earth magnet, while in rare earth magnet, NdFeB is the most powerful magnet. But in more than 200 degrees Celsius in the environment, is the most powerful magnet smco.


  • DC Electromagnet
  • Sintered Ferrite Speaker Ring
  • Cast AlNiCO Magnet
  • Strontium Ferrite Magnets
  • Ferrite Block Magnet
  • Mini Bluetooth Amplifier

Related Products