Dowell Industry Co.,Limited
Products Category

Name: Emily Yao
Add: 9/F Qiushi Building, 6 Jiaogong Road, Hangzhou, 310012, China


1.    What does a magnet do?
Magnets do the following things:

Attract certain materials - such as iron, nickel, cobalt, certain steels and other alloys;

Exert an attractive or repulsive force on other magnets (opposite poles attract, like poles repel);

Have an effect on electrical conductors when the magnet and conductor are moving in relation to each other;

Have an effect on the path taken by electrically charged particles traveling in free space.

Based on these effects, magnets transform energy from one form to another, without any permanent loss of their own energy. Examples of magnet functions are:

A.     Mechanical to mechanical - such as attraction and repulsion.

B.     Mechanical to electrical - such as generators and microphones.

C.     Electrical to mechanical - such as motors, loudspeakers, charged particle deflection.

D.     Mechanical to heat - such as eddy current and hysteresis torque devices.

E.      Special effects - such as magneto-resistance, Hall effect devices, and magnetic resonance.


2.    What are the different types of magnets available?

    There are 2 types of magnets: permanent magnets and electromagnets.

Permanent magnets emit a magnetic field without the need for any external source of power. Electromagnets require electricity in order to behave as a magnet.

3. What is a permanent magnet?

    A material which retains its permanent magnetic field after the external magnetising field has been removed.

 There are various different types of permanent magnet materials, each with their own unique characteristics. Each different material has a family of grades that have properties slightly different from each other, though based on the same composition.

4.    What is the best permanent magnet?

All permanent magnet materials have the advantages and disadvantages.  I recommend that you contact us if you wish to find out best material for your application.

5.    What are Rare Earth Magnets?
Rare earth magnets are magnets that are made out of the rare earth group of elements. The most common rare earth magnets are the neodymium-jron-boron. and samarium cobalt types.

The most powerful magnets available today are the rare earths types. Of the rare earths, neodymium-iron-boron types are the strongest. However, at elevated temperatures (of approximately 150 C and above), the samarium cobalt types can be stronger that the neodymium-iron-boron types (depending on the magnetic circuit).


6.    What is application?

Magnet Applications currently offers total magnetic solutions to a number of industries, including:

• Aerospace
• Automotive
• Communications
• Computers and Peripherals
• Magnetic Assemblies
• Medical Device and Diagnostics
• Motion Control
• Motors
• Research and Development
• Sensors
• Wind Power

7.    How permanent is a magnet's strength? What might affect a magnet's strength?

     If a magnet is stored away from power lines, other magnets, high temperatures, and other factors that adversely affect the magnet, it will retain its magnetism essentially forever.
The factors can affect a magnet's strength: Heat, Radiation, Strong electrical currents in close proximity to the magnetm, Other magnets in close proximity to the magnet, Neo magnets will corrode in high humidity environments unless they have a protective coating, Shock and vibration do not affect modern magnet materials, unless sufficient to physically damage the material.

8. How do you measure the strength or power of a magnet?
    Most commonly, Gaussmeters, Magnetometers, or Pull-Testers are used to measure the strength of a magnet. Gaussmeters measure the strength in Gauss, Magnetometers measure in Gauss or arbitrary units (so its easy to compare one magnet to another), and Pull-Testers can measure pull in pounds, kilograms, or other force units. Special Gaussmeters can cost several thousands of dollars. We stock several types of Gaussmeters that cost between $400 and $1,500 each.

9.    What are Magnetic Poles? How to identify if not marked?

     Magnetic Poles are the surfaces from which the invisible lines of magnetic flux emanate and connect on return to the magnet.

The North Pole is defined as the pole of a magnet that, when free to rotate, seeks the North Pole of the Earth. In other words, the North Pole of a magnet seeks the North Pole of the Earth. Similarly, the South Pole of a magnet seeks the South Pole of the Earth.
If not marked, you can't tell by looking. You can tell by placing a compass close to the magnet. The end of the needle that normally points toward the North Pole of the Earth would point to the South Pole of the magnet.

10.  What does 'orientation direction' mean?

     Most modern magnet materials have a "grain" in that they can be magnetized for maximum effect only through one direction. This is the "orientation direction", also known as the "easy axis", or "axis".

Unoriented magnets (also known as "isotropic magnets") are much weaker than oriented magnets, and can be magnetized in any direction. Oriented magnets (also known as "anisotropic magnets") are not the same in every direction - they have a preferred direction in which they should be magnetized.

11.  What are neodymium magnets? Why neodymium magnets coated?

     Neodymium magnets are a rare earth magnet and represent the strongest permanent magnets currently available! They are composed of neodymium, iron and boron (NdFeB).It has a grade of N35, N40, N42, N45, N48, N50, N52. Neodymium Magnets are graded by their magnetic energy, the higher the grade, the higher the magnetic energy.

Neodymium magnets are coated in three layers, Nickel-Copper-Nickel to prevent oxidiation (rust) which would damage the magnets strength. Rusting can take place if the protective plating is damaged.


12. Do magnets affect or damage electronic devices?

     As a general rule, try to avoid close contact between magnets and electronic media. More common items to be damaged are CRT televisions, CRT computer monitors and magnetically stored media (such as hard drives & credit cards).







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