Start to know about magnets
Most frequent questions and answers
No, we don’t, nor does anyone else, because they don’t exist. All magnets must have at least two poles.
No, once a magnet is fully magnetized (saturated), it cannot be made any stronger.
Here are the dimensions of these coins along with the closest matching magnet that we currently stock:
US Penny = 0.75″ dia. x 0.061″ ==> DC1 (0.75″ dia. x 0.063″)
US Nickel = 0.835″ dia. x 0.077″ ==> DE1 (0.88″ dia. x 0.063″)
US Dime = 0.705″ dia. x 0.053″ ==> DA1 (0.63″ dia. x 0.063″), DB1 (0.688″ dia. x 0.063″) or DC1 (0.75″ dia. x 0.063″)
US Quarter = 0.955″ dia. x 0.069″ ==> DX01 (1.0″ dia. x 0.063″)
US Half Dollar = 1.205″ dia. x 0.085″ ==> DX42 (1.25″ dia. x 0.125″)
The maximum operating temperature is the maximum temperature the magnet may be continuously subjected to with no significant loss of magnetic strength. This is 176oF (80oC) for standard grades of neodymium magnets. The Curie Temperature is the temperature at which the magnet will become completely demagnetized. This is 590oF (310oC) for standard grades of neodymium magnets. Higher temperature grades have higher maximum operating temperatures and higher Curie Temperatures. At temperatures between these two points, a magnet will permanently lose a portion of its magnetic strength. The loss will be greater the closer to the Curie Temperature it is heated.
As a general rule of thumb, a peak field of between 2 and 2.5 times the intrinsic coercivity is required to fully saturate a magnet. For standard neodymium magnets, the field required is minimum of 24 KOe, but 30 KOe is usually the minimum used.
According to the United States Department of Transportation and the Office of Hazardous Materials Safety, the limit for shipping magnets by air is a magnetic field strength of 0.00525 Gauss measured at 15 feet (4.5 meters) from any point on the outside of the package. There are no restrictions on the shipping of magnetized materials by ground. When in doubt, ship magnets by ground transportation.
Neodymium magnets are composed mainly of Neodymium, Iron, and Boron. If neodymium magnets are not plated, the iron in the material will oxidize very easily if exposed to moisture. Even normal humidity will rust the iron over time. To protect the iron from exposure to moisture, most neodymium magnets are plated or coated.
Choosing different coatings does not affect the magnetic strength or performance of the magnet, except for our Plastic and Rubber Coated Magnets. The preferred coating is dictated by preference or intended application. More detailed specifications can be found on our Specs page.
1) Nickel is the most common choice for plating neodymium magnets. It is actually a triple plating of nickel-copper-nickel. It has a shiny silver finish and has good resistance to corrosion in many applications. It is not waterproof.
2) Black nickel has a shiny appearance in a charcoal or gunmetal color. A black dye is added to the final nickel plating process of the triple plating of nickel-copper-black nickel. NOTE: It does not appear completely black like epoxy coatings. It is also still shiny, much like plain nickel plated magnets.
3) Zinc has a dull gray/bluish finish, that is more susceptible to corrosion than nickel. Zinc can leave a black residue on hands and other items.
4) Epoxy is basically a plastic coating that is more corrosion resistant as long as the coating is intact. It is easily scratched. From our experience, it is the least durable of the available coatings.
5) Gold plating is applied over the top of standard nickel plating. Gold plated magnets have the same characteristics as nickel plated ones, but with a gold finish.
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.
There are no known 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 or other implanted medical devices handling or being around strong magnets. We are not medical professionals, so we cannot offer complete guidance on pacemaker safety. We’ve shared what we do know in our article about Pacemaker Safety. Please consult a physician for this information. There are several safety concerns when handling strong magnets. Please refer to our Safety Page for complete details.
Yes, we do. If you have a website and would like to earn commissions for sales generated by your link to our store, please drop us an email or give a ring to us. Image this, if all cars become electrical one, our B2B magnetic side will have a potential increase, the more we use electricity, the more we need to build eco-friendly environment and clean energy, that is another potential market for us. Kyle Magnetics CO.,LTD is specialized in motor manufacturing, our Chinese factory zhonghangkeji is the largest motor magnet manufacturer in the world, became public traded last year. Devoting ourselves in clean energy and prevents global-warming effect with our professional knowledge in magnetic materials !
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The Rules & Regulations
An aircraft “wet” compass
There are two important measurements of a package containing magnets. Rule #1: If the field strength is 2 milligauss (0.002 gauss) or more at a distance of 7 feet from the package, the IATA (International Air Transport Association) says the package needs to be labeled as Magnetic. This is especially applicable for international shipments.
Magnets are often shipped in a steel-lined box to remain below this limit.
If there is any chance that the arrangement of magnets could change, or any package shielding could be damaged so that a measurement exceeds this value, it falls under the Dangerous Goods category and should be labeled as Magnetic.
Rule #2: For any package shipped by air, whether it is labeled magnetic or not, the field strength must be 5.25 milligauss or less at a distance of 15 feet from the surface of the package (FAA Title 49, Part 173.21 Forbidden materials and packages). If the package measures above this value, don’t ship it by air.
Why are these rules so important? The magnetic compass. Despite all the fancy GPS navigation systems, the basic compass is still an important part of aircraft navigation. If a cargo of magnets alters the compass readings, accurate navigation might be compromised.
Remember, your magnets are competing with the magnetic field of the Earth, whose strength is only about 0.5 gauss on average.