This section provides an overview for ferrite magnets as well as their applications and principles. Also, please take a look at the list of 11 ferrite magnet manufacturers and their company rankings. Here are the top-ranked ferrite magnet companies as of June, 2023: 1.Sinotech, 2.Magnetic Component Engineering, Inc., 3.Alliance LLC.
Table of Contents
Ferrite magnets are made by mixing iron oxide with cobalt, nickel, and manganese. The molecular formula is represented as MFe2O4 (M = Mn, Fe, Co, Ni, Cu, Mg, Zn, Cd, etc.).
The composite metal M is dominated by divalent cations, and Fe3O4, where M = Fe, is black and is a well-known raw material called magnetite. Other compounds exist where the compound metal M is 1, 3, or even tetravalent cations, called ferrite.
The manufacturing process involves pressing powdered ferrite and baking it at high temperatures. It is also a type of ceramic. It can be synthesized from iron oxide Fe2O4 and is therefore inexpensive.
The characteristics of ferrite magnets are that they can be easily formed into any shape and are easy to process, and that they are chemically stable and resistant to corrosion by rust and chemicals.
Applications of ferrite magnets can be divided into two types: hard ferrite and soft ferrite.
Hard ferrite magnets are ferrite magnets that become permanent magnets once they are attached to a strong magnet (by applying a strong magnetic field). U-shaped magnets are the most common type of magnet we see in our daily lives.
U-shaped magnets are typical examples. They are also used in small motors, speakers, headphones, and cassette tapes.
Soft ferrite is a ferrite magnet that becomes a magnet when in contact with a magnetic field and ceases to be a magnet when removed from the field. It is often used as a magnetic core and is suitable for transformers and coils.
Examples of easy-to-understand applications are used in radios, televisions, game consoles, automobiles, personal computers, microwave ovens, vacuum cleaners, and refrigerators.
The magnetic properties of ferrite magnets differ between hard ferrites and soft ferrites. First, let us explain the magnetic properties. Figure 1 shows the spin state of each magnetic property.
The types and characteristics of each type of ferrite magnet are shown in Figure 2. Saturation magnetization is the maximum magnetization at which the magnetization of a material does not increase even if the magnetic field is increased. Curie temperature is the temperature at which the magnet changes from ferromagnetic to paramagnetic.
Hard ferrite is a ferromagnetic material and a permanent magnet. Hard ferrites can be further classified into isotropic and anisotropic magnets according to the orientation of the magnetic poles of their molecules.
Soft ferrite is magnetic only while an external magnetic field is applied. Although the magnetic field is smaller than that of hard ferrite, it has excellent magnetic properties over a wide frequency range.
For example, a spinel-type crystal structure has a high magnetic permeability (the degree to which a material is magnetized) over a wide range of frequencies. The garnet type has the property that single crystals are not easily broken in the microwave frequency range.
Alnico magnets are manufactured by adding aluminum (Al), nickel (Ni), cobalt (Co), and other additive elements to iron and using casting methods or powder sintering.
Alnico magnets are characterized by their extremely high Curie temperature (the temperature at which they cease to be permanent magnets) of 860°C, allowing them to be used in high-temperature environments. Alnico magnets can recover their original magnetic force when returned to room temperature at temperatures ranging from room temperature to 400℃. Those manufactured by casting also have excellent mechanical strength.
Applications for Alnico magnets include electric motors, sensors, speaker units, and magnetic pickups for electric guitars.
Ferrite magnets are primarily composed of iron oxide, while Alnico magnets are composed primarily of iron with aluminum, nickel, and cobalt added. The retention of magnetic force in an Alnico magnet is small and easily demagnetized.
There is a limitation that they must have a long shape due to the need for a long distance between the poles. Also, the supply of the raw material, cobalt, is unstable and expensive, so ferrite magnets are less expensive.
Samarium cobalt magnets are rare earth magnets composed of samarium (Sm) and cobalt (Co). They are divided into SmCo5 (1-5 series) and Sm2Co17 (2-17 series) according to their composition ratio, with the 1-5 series, which contains less samarium, being widely used today.
Samarium cobalt magnets are characterized by a high Curie temperature of approximately 800°C at maximum. Because of its excellent corrosion resistance, it can be used as is without surface treatment, and its shape is highly selectable. Magnetic properties are higher than those of ferrite magnets and second only to those of neodymium magnets.
Because they can be used in environments up to about 350°C, they are used in space-saving, high-temperature environments where higher magnetic force than ferrite magnets is required. On the other hand, it has the disadvantage of low strength, which makes it prone to cracking and chipping. The raw materials samarium and cobalt are both rare, making it very expensive compared to ferrite magnets.
A neodymium magnet is a magnet composed mainly of neodymium (Nd), iron (Fe), and boron (B). Neodymium magnets are characterized by their easy oxidation and high thermal dependence.
Because they oxidize easily, their surfaces are nickel-plated before use. They are usually used at temperatures below 80°C. Because of its relatively high strength, it is also resistant to cracking and chipping.
Compared to ferrite magnets, magnetic properties are extremely high, with about four times the magnetic holding power and 10 times the maximum energy product. It is more expensive than ferrite magnets, but less expensive than samarium cobalt magnets.
*Including some distributors, etc.
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Bunting was founded in 1959 and is headquartered in Newton, Kansas. The company is a family-owned manufacturer of standard and custom magnetic components for domestic and international customers from industries such as food processing, plastics, recycling, and mining. The company’s main product lines include magnetic separation, metal detection material handling equipment, printing products, and custom magnets & magnetic assemblies. Custom designs include materials such as ceramic ferrite, alnico, and samarium cobalt and are made for Halbach arrays, pump couplings, actuators, and other components.
Bunting Dubois began in 1959 as Bunting Magnetics, Co. in Chicago, Illinois as a magnet manufacturer. Today, the company is based in Bunting, Pennsylvania, has attained ISO 9001:2015 certification, and manufactures a full range of magnetics manufacturing with both ferrite and rare earth compounds for consumers around the world in industries spanning aerospace, automotive, medical, and industrial manufacturing. The company seeks to source magnetic material outside of China in conflict-free areas and performs 100% of manufacturing inside the United States. The company assists customers by providing engineering and application support to produce solutions, especially in the case of rare earth magnets.
Sinotech is based in Portland, Oregon with offices in China. Sinotech is a distributor for custom-engineered electrical motors, motor components, and mechanical components manufactured in China. Sinotech’s motors include AC motors, DC motors, brushless DC motors, slotless high speed BLDC motors, stepper motors, cordless motors, gear motors, servo motors, and miniature motors. Motor components include laminations, wound coils, armature and field coils, brushes, and communicators. Mechanical components include assemblies, die castings, investment castings, sand castings, shafts, steamed metal parts, tubular metal parts, machined extrusions, plastic parts, rubber parts, and secondary processing.
READE was originally established in Wolverhampton, England in 1773 as a pharmaceutical chemical and varnish manufacturer. Today READE is based in Riverside, Rhode Island in the United States and is an ISO 9001-certified distributor of specialty chemical solids. READE Advanced Materials offers a selection of hundreds of materials and compounds ranging from alloys in various forms to oxides, sulfides, individual elements, and specialty compounds. READE offers global sourcing, custom toll chemical processing, and custom toll packaging from metallurgical grade to pharmaceutical and food grade.
Celduc Inc. through Celduc Transfo was founded in 1960 as a manufacturer of transformers. Celduc Inc. is based in, France. Celduc Inc. was officially created in 2020 and headquartered in Centerport, New York. Celduc creates electronics and customized products for industries including railway, plastic, packaging, medical, and electronics. Celduc’s main product lines include solid state relays, magnetic proximity sensors, reed relays & switches, and customized products. Customized products are versions of other products adapted for use in industries with special needs such as nuclear power, aircraft, and agriculture.
Ranking as of June 2023 in United States of America
Derivation MethodRank | Company | Click Share |
---|---|---|
1 | Sinotech | 17.2% |
2 | Magnetic Component Engineering, Inc. | 13.8% |
3 | Alliance LLC | 13.8% |
4 | Bunting-DuBois | 10.3% |
5 | MARUWA CO., LTD. | 10.3% |
6 | Hitachi Metals, Ltd. | 10.3% |
7 | Bunting-Newton | 6.9% |
8 | Tridus Magnetics & Assemblies | 3.4% |
9 | CMI Integrated Technologies | 3.4% |
10 | Pacific PAC Technologies, Inc. | 3.4% |
11 | Reade Advanced Materials | 3.4% |
12 | Celduc Inc. | 3.4% |
Ranking as of June 2023 Globally
Derivation MethodRank | Company | Click Share |
---|---|---|
1 | Sinotech | 20% |
2 | Magnetic Component Engineering, Inc. | 13.3% |
3 | Alliance LLC | 13.3% |
4 | Bunting-DuBois | 10% |
5 | MARUWA CO., LTD. | 10% |
6 | Hitachi Metals, Ltd. | 10% |
7 | Bunting-Newton | 6.7% |
8 | Tridus Magnetics & Assemblies | 3.3% |
9 | CMI Integrated Technologies | 3.3% |
10 | Pacific PAC Technologies, Inc. | 3.3% |
11 | Reade Advanced Materials | 3.3% |
12 | Celduc Inc. | 3.3% |
Derivation Method
The ranking is calculated based on the click share within the ferrite magnet page as of June 2023. Click share is defined as the total number of clicks for all companies during the period divided by the number of clicks for each company.Number of Employees
Newly Established Company
Company with a History