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Frequently Asked Questions(FAQ)

Q: What are neodymium magnets?
A: Neodymium magnets are the strongest permanent magnets in the world. They are composed of Neodymium Iron and Boron. Also called NdFeB magnets.
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Q: Neodymium magnets are the same as "rare earth"?
A: Neodymium magnets are a member of the rare earth magnet family. SmCo and NdFeB magnets are the two kinds of rare earth magnets.They are called "rare earth" because neodymium is a member of the "rare earth" elements on the periodic table. Neodymium magnets are the strongest of the rare earth permanent magnets in the world.
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Q: What are neodymium magnets made from and how are they made?
A: Neodymium magnets mainly are composed of neodymium, iron and boron. The powdered mixture is pressed under great pressure into molds. Then sintered (heated under a vacuum), cooled, and ground or sliced into the desired shape. Coatings are then applied if required. Finally, the blank magnets are magnetized.
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Q: Are neodymium magnets the strongest?
A: Yes, Neodymium magnets are much stronger than any other permanent magnet available today. Neodymium magnets are about 10 times stronger than cerramic or ferrite magnets.
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Q: What does the grade of the magnets mean?
A: Neodymium magnetic material comes in different grades with different capabilities. In general, the grades balance the thermal capabilities of the material with the maximum energy product.
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Q: Does stacking magnets together become stronger?
A: Yes, two or more magnets stacked together will behave exactly like a single magnet of the combined size. For example, if you stacked two of our disc magnets to form a 1" x 1/2" combined size, the two magnets would have the same strength and behave identically to our discs, which are 1" diameter x 1/2" thick.
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Q: What are Magnetic Poles?
A: Magnetic Poles are the surfaces from which the invisible lines of magnetic flux emanate and connect on return to the magnet.
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Q: How to identify the poles of the magnets?
A: There are some simple methods can be used to identify the North and South poles of magnets.
  • To use another magnet that is already marked. The North pole will be attracted to the South pole.
  • If you have a compass handy, the end of the needle that normally points North will be attracted to the South pole of the magnet.
  • Gaussmeters can inspect the “N:”and “S” precisely and directly.
  • Use one of our Pole Identifier Devices.
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Q: What does "Magnetized through thickness" mean?
A: We describ "Magnetized thru thickness" to identify the locations of the poles on our magnets. The thickness is always the last dimension listed for magnets. For example: one block magent 1" x 1/2" x 1/4" thick. If you place one of the blocks so it is on a flat surface with 1/4" as the vertical dimension, the poles will be on the top and bottom as the magnet sits. This means the poles are located in the middle of the 1" x 1/2" sides.
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Q: How is the strength of magnets measured?
A: Gaussmeters are used to measure the magnetic field density at the surface of the magnet. This is referred to as the surface field and is measured in Gauss. Sometimes it is measured in Tesla. Pull Force Testers are used to test the holding force of a magnet that is in contact with a flat steel plate.
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Q: What is pull force and how to measured?
A: The force required to pull a magnet free from a flat steel plate using force perpendicular to the surface.
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Q: Will a magnet with a 50 lb pull force can lift a 50 lb object?
A: Because pull force values are tested under laboratory conditions, you probably won't achieve the same holding force under real world conditions. The effective pull force is reduced by uneven contact with the metal surface, pulling in a direction that is not perpendicular to the steel, attaching to metal that is thinner than ideal, surface coatings, and other factors.
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Q: Can you supply BH Curves, or Demagnetization Curves for your magnets?
A: Yes, we've posted BH-CURVE MAGNETOMETER and Demagnetization Curves for our most common Neodymium magnet grades right here.We also provide PCT,HAST,SST and so on.
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Q: Are your Neodymium Rare Earth Magnets RoHS compliant?
A: Yes, our magnets are fully RoHS compliant, meeting the European Parliament Directive entitled "Restrictions on the use Of Hazardous Substances" (RoHS). This Directive prohibits the use of the following elements in electrical/electronic equipment sold after 7/1/2006: cadmium (Cd), lead (Pb), mercury (Hg), hexavalent chromium (Cr(VI)), polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs).
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Q: What is the gauss rating of your magnets?
A: This depends on the context it is used. Most magnetic therapy people like to present the largest number possible, so they often use theResidual Flux Density (Brmax) of the material, which really doesn't specify much about the actual magnet. This value is essentially the magnetic field density inside the magnet material. Since you will never be inside the magnet, or using the field inside the magnet, this value doesn't really have any practical value. The surface field of a magnet is a much more accurate specification for a magnet. The surface field is exactly what it sounds like. It is the magnetic field density at the surface of the magnet as measured by a Gaussmeter. This value is tested and specified for each of our stock magnets.
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Q: Will magnets corrode?
A: NdFeB magnets are easy to corrosion. The 'Fe' in the name stands for Iron, and it rusts! Many of our magnets come with a Nickel, Zinc, Gold or Epoxy coating to protect them from moisture. If the coating is damaged, the magnet could rust if exposed to water or humidity. If this is a concern to you, you can easily add another layer of protection by dipping the magnet in epoxy or plastic coating.
But ferrite and Smco magnet not need coating ,they are highl resistant to Corrosion.
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Q: What is the thickness of the nickel (Ni-Cu-Ni) plating?
A: The nickel plating is actually triple plating of nickel-copper-nickel. The layers are Ni: 5-6µm, Cu: 7-8µm, Ni: 5-6µm, for a total thickness of 17-20µm.
You can look our available coating of sintered NdFeB Magnets on our website
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Q: I noticed that the plastic- and rubber-coated magnets have a lower pull force than nickel-plated magnets of the same size. Does the plastic/rubber weaken the magnet?
A: These materials don't "weaken" the magnet, but the volume of magnet material is reduced to allow room for the coatings, which reduces the pull force. The layer of plastic or rubber also creates distance between the magnet and metal surface which also reduces the pull force.
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Q: How does temperature affect the permanent magnet?
A: Yes. Neodymium Iron Boron magnets are sensitive to heat. If a magnet heated above its maximum operating temperature (176°F (80°C) for standard N grades) the magnet will permanently lose a fraction of its magnetic strength. If they are heated above their Curie temperature (590°F (310°C) for standard N grades), they will lose all of their magnetic properties. Different grades of neodymium different maximum operating and Curie temperatures.
Curie Temperature (Tc): This is the temperature at which a magnet material loses it's strength, permanently. Another useful number (if available) is Tmax, the recommended maximum operating temperature. Above Tmax (around 266 deg. F for most NdFeB magnets) a magnet will start ot lose its power, and at Tc all power is lost. If you need strong magnets that can be used at high temperatures, consider using Samarium Cobalt (SmCo) magnets
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Q: Will neodymium magnets lose strength over time?
A: Hardly not. Neodymium magnets are the strongest and most permanent magnets . If they are not overheated or physically damaged, neodymium magnets will lose less than 1% of their strength over 10 years - not enough for you to notice unless you have very sensitive measuring equipment. They won't even lose their strength if they are held in repelling or attracting positions with other magnets over long periods of time.
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Q: How do I separate large magnets?
A: Small and medium-sized magnets can usually be separated by hand by sliding the end magnet off of the stack. Medium-large magnets can often be separated by using the edge of a table or countertop. Place the magnets a table top with one of the magnets hanging over the edge. Then, using your body weight, hold the magnet(s) on the table and push down on the magnet hanging over the edge. With a little work and practice, you should be able to slide the magnets apart. Just be careful that they don't snap back together once they become separated. For very large magnets (generally 2" and larger), we use a specially made magnet separating tool.
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Q: How are magnets manufactured?
A: Manufacturing: NdFeB magnets are complicated to manufacture. The powdered NdFeB material is packed in molds, then sintered. The non-magnetized 'magnets' are then shaped to the correct size and plated. To magnetize them, they are placed an extremely high-powered magnetic field for an instant, using high-voltage capacitor discharge and coils. The polarity of the finished magnet depends on how it was oriented in the magnetizing machine, and how the particles in the sintered mixture were oriented. So that makes home manufacture impossible.
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Q: Can I cut, drill or machine magnets to my own sizes and shapes?
A: If AlNiCo magnets they are very easy to machine in any way you want. If NdFeB magnets they are very hard and brittle. Although they can be cut, drilled and machined, it should only be done by folks who are experienced. They are flammable, and it is difficult while grinding or machining to get them (or the chips and dusts from cutting) so hot they ignite. If they do ignite, the fumes are toxic and the material burns very fast and hot, like Magnesium! In our experience any machining of these magnets should be done with diamond tools under lots of coolant with good ventilation and the risk of fire in mind.
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Q: Why magnet shipped by air is difficult?
A: According to the United States Department of Transportation and the Office of Hazardous Materials. We take great care when packing orders to see that any magnetic fields are well contained within the box we send them in. We pack very carefully so the external magnetic fields cancel out, and we use steel box liners as needed to insure that every box is safe and non-magnetic to comply with.
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Q: Safety issues should be aware of when handling magnets?
A: Keep magnets out of reach of children! Although magnets can be wonderful toys and highly educational, Small children should not be allowed to handle any of our magnets at all! Surprise is the main issue -- most folks are not aware of how powerful large magnets are.
And for adults take them carefully or your finger and hand will be Clip broken.
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Q: Are there health or safety concerns with neo magnets?
A: There are no health concerns with exposure to permanent magnetic fields. In fact, many people believe that magnets can be used to speed up the healing process. There may be issues with people with pacemakers handling or being around strong magnets. Please consult a physician for this information. There are several safety concerns when handling strong magnets.
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Q: Will magnets harm my electronics?
A: Maybe...The strong magnetic fields of these magnets can damage certain magnetic media such as floppy disks, credit cards, magnetic I.D. cards, cassette tapes, video tapes or other such devices. They can also damage televisions, VCRs, computer monitors and other CRT displays. Never place neodymium magnets near any of these appliances. As for other electronics such as cell phones, iPods, flash drives, calculators and similar devices that do not contain magnetic storage media, probably not, but it is best to err on the safe side and try to avoid close contact between neo magnets and electronics.
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Q: How to assemble the magnetic component?
A: Either by fixturing or gluing to combine magnet and other parts together. The assembling process should be completed by those experienced professionals. Our comapny has such experience of MRI, magnetic fridge installation. We have the ability to provide assembling service to all kinds of magnetic components.
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