Explaining the Direction of Magnetization and Orientation of a Magnet
August 22, 2016
Magnets come in many shapes, sizes, and materials. Whether you need a disc magnet, cylinder magnet, ring magnet, or custom shaped magnet, picking the correct magnet, and its direction of magnetization for your application is critical.
Very often we get questions about the meaning of “Direction of Magnetization.” There are so many terms in our magnetics glossary, but for this post, we will only define, “Anisotropic”, “Orientation” and “Direction of Magnetization” which will help define why a magnet is magnetized the way it is magnetized.
Periodically, we get a request to change the “Direction of Magnetization” with one of our stock parts. The requests usually ask if we are able to change the direction of magnetizing from width to length, length to across the diameter, or even diagonally. While our stock magnets have a set direction of magnetization, we can manufacture custom magnets to meet a customer’s requirements. But, let’s begin by explaining why a magnet’s direction of magnetization cannot be changed on a finished magnet.
An anisotropic magnet is a magnet that has a defined direction of orientation, or alignment, that is determined during the manufacturing process. When an anisotropic magnet is manufactured it is pressed in a very strong magnetic field, which aligns the domains inside of a magnet. Once these domains are aligned they cannot be changed. So, for example, a magnet pressed in a magnetic field that aligns the domains through the length of the magnet can only be magnetized with the direction of magnetization through the length.
“Direction of Orientation” vs “Direction of Magnetization”
So what is the difference between “Direction of Orientation” vs “Direction of Magnetization”? They can actually be interchangeable terms, but for purposes of this conversation we will break them into separate terms.
Direction of Orientation
The Direction of Orientation refers to the alignment of the domains inside of the magnet during the pressing process and prior to magnetization. As mentioned above, when a magnet is manufactured it is pressed in a very strong magnetic field. This pressing process does not make the magnet “magnetic”, but only sets the direction of the domains inside of the magnet, which defines the Direction of Orientation. The magnet still needs to go through several other manufacturing steps after the pressing process, but none of these steps are able to change the orientation, or alignment, of the domains inside of the magnet.
Direction of Magnetization
Once the magnet has completed the entire manufacturing process, the last step prior to packaging is Magnetizing. All through the manufacturing process the magnet is similar to a piece of steel, it is a ferrous material, but not magnetized. The magnetization process involves putting the non-magnetized magnet into a magnetizing system and pushing a large volume of electricity through the magnet. This makes all of the domains inside of the magnet point exactly in the same direction, thus creating a magnetic north and south pole.
Examples of different types of magnetism:
Through the thickness:
Through the length:
Across the width:
Across the diameter:
So, can we magnetize a magnet in a different direction by putting it inside of the magnetizing coil in a different direction? No, because the orientation of the magnet was set during the pressing process and can only be magnetized in that direction no matter what direction they are placed in the magnetizing coil.
What if I need a magnet oriented in a different direction?
Magnets can be oriented in almost any direction, but the specifications of the magnet must be determined prior to manufacturing. We work with hundreds of customer every year from design to production to help determine their magnet needs, which involves the orientation of the magnet. If you have an application that requires the orientation of a magnet to be different then a stock item, you can contact us at email@example.com, or use our Custom Magnet Request Form.
To learn more about how super magnets are made, watch our video: