Magnet Portfolio
China Neodymium Magnet
JDA Magnet, a neodymium magnet manufacturer in China for over 25 years, offers professional China-based certified neodymium magnets for all purposes and applications
Neodymium Disc
Neodymium Ring
Neodymium Block
Neodymium Arc
Neodymium Trapezoid
Neodymium Mounting
China Magnetic Assembly
By leveraging the expertise of our skilled team, we can design and manufacture custom magnetic assemblies tailored to meet your specific requirements and challenges.
Magnetic Couplings
Magnetic Bar
Magnetic Plate
Pot Magnet
China Magnet Manufacturing Process
Step 1：Combination of Metals
Controlling the suitable component ratio of heavy rare-earth elements and some micro-quantity additives for custom sintered NdFeB magnets is the basic method to obtain the required magnet grade and magnetic properties.
Step 2: Melting & Strip Casting
The alloy, with a nominal composition of neodymium rare-earth alloys, iron, boron, and other additive elements, is melted by a vacuum induction melting furnace from industrial-grade raw materials with purity above 99.5% and followed by the strip casting (SC) technique into SC alloys.
Step 3: Pulverization
The strips are crushed and further processed by the hydrogen decrepitation (HD) crushing into coarse fragile particles. These coarse particles were further milled by jet milling (JM) until the particle size was about 3-4 μm.
Step 4: Pressing in Magnetic Field
The alloy, with a nominal composition of neodymium rare-earth alloys, iron, boron, and other additive elements, is melted by a vacuum induction melting furnace from industrial-grade raw materials with purity above 99.5% and followed by the strip casting (SC) technique into SC alloys.
Step 5: Sinter & Heat Treatment
The green compacts are then densified by sintering in a vacuum at a temperature over 1000°C. Post-sintering heat treatment in a vacuum at about 600°C is also necessary to enhance the coercivity of the magnet.
Step 6: Machining
The green compacts are then densified by sintering in a vacuum at a temperature over 1000°C. Post-sintering heat treatment in a vacuum at about 600°C is also necessary to enhance the coercivity of the magnet.
Step 7: Plating
A thin layer of material applied to the outside of a magnet to prevent corrosion. Neodymium magnets are the most prone to corrosion and the most likely to require a coating. Various coatings applied to permanent magnets, including Ni-Cu-Ni, Zn, Epoxy, etc.
Step 8: Magnetize
Magnetization orientation determines the magnetic polarity and position of one magnet pole relative to the other. It is the last step in the production process to achieve optimum magnetic properties.
Step 9: Packaging & Shipping
Huge care and expertise are employed in packing neodymium magnets. It’s packed with metal plate for anti-magnetization required for air shipping. Large network with the most advanced airlines ensure delivery at cost and on time.
Frequently Asked Questions
Purchasing Questions
No MOQ, but the price depends on the quantities.
We provide our customers one-stop solutions in technique, manufacturing, and delivery if needed, based on our many years of experience in the industry.
It depends on the needed magnetic propertities, and the speed of customs clearance and logistics, but we can guarantee to finish magnets in less than 20 working days.
50% T/T in advance, balance before shipment.
No, we don’t have a pricelist. All magnets are customized in grade, shape, size, and coating, so the price would be quoted per as your specifications.
We are a factory. Meanwhile, we have our own trading company for exporting. We offer factory direct prices with excellent quality and worry-free service.
Yes, size, shape, color, logo printing, etc are welcomed.
We have 1:1 replacement for the defective magnets if the problems at our side.
Yes, we offer samples free of charge for your testing, but courier cost at your side.
Of course, welcome to visit our factory or hire a third-party organization to inspect. Also, it’s available to offer on-site photos, vedios, and start on-line video to view factory and production line
We offer you a 1 years warranty on our high-quality neodymium magnets and lifetime technical support.
Magnet Properties and Strength
Neodymium magnets are the strongest type of permanent magnet available.
No, both poles of a magnet have equal strength.
Yes, stacking magnets together can make them stronger, but only if they are stacked in a way that aligns their poles.
It means the magnetic field runs from one flat surface to the other through the thickness of the magnet.
No, neodymium magnets will not lose their strength significantly when held in repelling or attracting positions for extended periods, as long as they are not subjected to extreme temperatures or other adverse conditions.
The maximum operating temperature is the highest temperature at which a magnet can function without significant loss of its magnetic properties. The Curie temperature is the temperature at which a magnet loses its magnetic properties entirely and becomes demagnetized.
Magnets attract ferromagnetic materials such as iron, nickel, and cobalt.
Materials like Mu-metal or high-permeability magnetic shielding alloys can block or shield magnetic fields.
The strength of a magnet is typically measured using its maximum energy product, usually denoted as (BH)max, or by its pull force.
Not necessarily, as other factors like surface conditions, shape, and size of the object also play a role in determining the effective lift.
Different grades of neodymium magnets represent variations in the maximum energy product (in Mega-Gauss-Oersteds or MGOe) and temperature resistance. The grade is typically indicated by a letter (e.g., N, M, H) and a number (e.g., 35, 42, 52). The number refers to the magnet’s maximum energy product, while the letter denotes its temperature resistance.
Neodymium magnets can last for decades if they are not subjected to extreme temperatures, excessive mechanical stress, or corrosive environments.
Neodymium magnets are brittle and can break, crack, or chip if subjected to mechanical stress, such as being dropped or impacted. They should be handled with care to avoid damage.
Cutting, drilling, or machining neodymium magnets is difficult and not recommended. Doing so can cause the magnet to crack, chip, or shatter, generating heat, which can demagnetize the magnet.
Neodymium magnets can lose some or all of their magnetization if exposed to temperatures exceeding their maximum operating temperature or approaching their Curie temperature.
Usage Questions
We can provide BH or demagnetization curves for their magnets upon request.
Pull force is determined by measuring the force required to separate a magnet from a flat, thick steel plate under controlled conditions. It can be affected by magnet size, shape, grade, and surface conditions.
A magnetic field is invisible but can be visualized as lines of force extending between the north and south poles of the magnet. The field is strongest near the poles and weakens as you move further away.
Yes, our magnets are RoHS compliant, which means they are free of hazardous substances like lead, mercury, and cadmium.
Neodymium magnets do not generally require a keeper, as they have a high coercivity and are less likely to lose their magnetization. However, a keeper may be useful in certain applications to protect the magnet from mechanical damage or to enhance its magnetic field.
No, its magnetic strength cannot be increased once a magnet is manufactured. However, you can enhance the magnetic field by stacking magnets or using magnetic circuit designs to focus the field in a specific area.
Neodymium magnets lose a very small percentage of their strength over time, usually less than 1% over a decade. They will retain their magnetism for many years, provided they are not exposed to extreme temperatures, mechanical stress, or corrosive environments.
Yes, neodymium magnets are sensitive to temperature. Exposure to temperatures above their maximum operating temperature can cause them to lose some or all their magnetization. Choosing a magnet with an appropriate maximum operating temperature for your specific application is crucial.
Magnets work due to the alignment of electrons within their atoms. The electrons’ magnetic moments align in magnetic materials, creating a magnetic field that attracts or repels other magnetic materials.
Strong magnets, such as neodymium magnets, can potentially damage or erase data on hard drives or other magnetic storage devices if they come in close proximity. However, magnetic fields do not affect most computer components, like solid-state drives (SSDs) and processors. It is recommended to keep strong magnets away from sensitive electronic devices.
As a general guideline, keep strong magnets at least a few inches away from sensitive electronics. The safe distance may vary depending on the magnet’s strength and the device’s sensitivity
Neodymium magnets are generally safe to handle but can cause injuries if not used properly. They can pinch skin or fingers if they snap together suddenly, and small magnets can pose a choking hazard. Always follow safety guidelines and keep them away from children.
Strong magnets can damage or erase data on magnetic storage devices (e.g., hard drives) and affect the functioning of some electronic devices. Keep strong magnets away from sensitive electronics to avoid any issues.
You can remove metal dust from your magnets by using a soft cloth, plastic scraper, or a piece of tape. Be gentle to avoid scratching the magnet’s surface, and safely dispose of the metal dust.
To separate large magnets, use a wooden or plastic wedge and carefully slide it between them, applying steady and even pressure. Keep your fingers away from the edges to avoid getting pinched.
To store neodymium magnets, keep them away from heat, moisture, and corrosive environments. Place them in a cool, dry location and separate them from other magnetic materials or electronic devices. Use spacers or dividers to prevent strong magnets from attracting one another and causing injury or damage. If necessary, use a protective case or container to store them safely.
Application Questions
Neodymium magnets are used in a wide range of applications due to their high magnetic strength and versatility. Some common uses include motors, generators, sensors, consumer electronics, medical devices, and magnetic holding systems.
Some common applications of neodymium magnets include: Electric motors and generators, Wind turbines, Hard disk drives, Magnetic resonance imaging (MRI) machines, Magnetic levitation systems, Headphones and speakers.
Latches and closures
Magnetic separators
Yes, neodymium magnets can be used for magnet fishing. In this popular activity, people use strong magnets attached to a rope to find metal objects submerged in water bodies like lakes, rivers, and ponds.
Using neodymium magnets to remove security tags is not recommended and may be illegal. Security tags are designed to be removed by authorized personnel using special tools in retail establishments.
Yes, neodymium magnets are commonly used in speakers, including headphones, due to their high magnetic strength, which helps produce better sound quality and a more compact design
Magnetic assemblies combine magnets with other materials, such as metals, plastics, or rubber, to create a functional unit with specific properties or applications. These assemblies can enhance the magnetic field, provide mechanical support, or offer additional functionalities, such as mounting or movement. Some examples of magnetic assemblies include magnetic hooks, filters, and couplings.
Shipping Questions
Shipping magnets in a small envelope is unavailable, as strong magnetic fields can interfere with navigation equipment and electronics. To ensure safe and compliant shipping, follow guidelines set by shipping carriers, such as proper packaging and labeling.
To protect your magnets from damage, handle them carefully and store them with a cushioning material, such as foam or bubble wrap. Keep them away from areas where they might be dropped or subjected to mechanical stress. Consider using them in a device or assembly with a protective casing or enclosure.
Yes, there are regulations for shipping magnets, as strong magnetic fields can interfere with navigation equipment and electronics. Magnets must be packaged and shipped according to the guidelines set by organizations such as the International Air Transport Association (IATA) and the United States Postal Service (USPS).
Manufacturing Questions
Neodymium magnets are made from an alloy of neodymium, iron, and boron (NdFeB). These elements give the magnets strong magnetic properties, making them the most powerful commercially available permanent magnets.
Neodymium magnets are made by melting the alloy of neodymium, iron, and boron and then cooling the mixture in a mold to form an ingot. The ingot is then ground into a fine powder and pressed into the desired shape under high pressure. Finally, the pressed magnet is sintered at high temperatures to solidify the material and then magnetized, cut, and coated as needed.
Yes, China is the world’s largest producer of rare earth materials, including neodymium. China holds a significant portion of the global rare earth reserves and has a dominant position in producing and exporting rare earth elements.
Yes, you can paint over the nickel plating on neodymium magnets. However, ensure the surface is clean and dry before applying paint. Use a primer suitable for metal surfaces, followed by a compatible paint, to ensure proper adhesion and protection.
Most neodymium magnets are plated or coated to protect them from corrosion, as the NdFeB alloy is prone to oxidation. Common coatings include nickel, zinc, and epoxy, which help prevent the magnet from rusting and maintain its magnetic properties.
The thickness of the nickel plating on neodymium magnets can vary depending on the manufacturer and application requirements. Typically, it ranges from 10 to 30 micrometers (µm) or more. The plating often consists of a layered structure with nickel, copper, and nickel layers, which provides better adhesion and corrosion resistance.
The most common coatings for neodymium magnets include Nickel (Ni-Cu-Ni), Zinc, Epoxy, and Gold.
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