Neodymium Magnet 101
Neodymium Magnets ( NdFeB Magnets ) were invented in 1980s and soon have become the major permanent magnets in replacing the old magnets for improved performance. The major reason is because of its wonderful magnetic characteristics, and specifically its strength and stability.
Neodymium magnets have a higher Maximum Energy Product, i.e. (BH)max than SmCo magnets (Samarium Cobalt magnets). (BH) max of neodymium magnets can easily reaches 30 MGOe and even goes up to 52 MGOe. Neodymium magnets can replace SmCo magnets in most cases, especially where the operating temperature is less than 80 degree Centigrade, though the temperature stability of neodymium magnets is not as good as SmCo magnets. The magnetic performance of the regular neodymium magnets will go down rapidly around 80 degrees Celsius but the specially made ones can work up to 220 degree Celsius. Compared to SmCo magnets, the corrosion and oxidation resistance of neodymium magnets are relatively low.
Sintered neodymium magnets are made with several steps. At first, a Nd-Fe-B alloy is formulated based on the magnetic characteristics of final permanent magnets supposed to reach. The alloy is produced in a vacuum furnace. Then the alloy is crushed into a powder form. Sintered neodymium magnets are formed by powder metallurgical process. These magnets can be die pressed or isostatically pressed. During the pressing process, magnetic fields are applied with assistance of specially designed fixture to align magnetic "domains" and optimize the magnetic performance of these magnets. Then pressed magnets are placed into a furnace under protective atmosphere for sintering. After sintering the magnet shape is rough, and need to be machined and ground to achieve desired shape and tolerances. A surface coating is usually applied on neodymium magnets. Zinc or nickel coating is common used as a protective layer. Other materials such as cadmium chromate plating or aluminum chromate plating, tin or polymer (epoxy) are also used for this purpose.
Both neodymium magnets and SmCo magnets can be made either in sintered or polymer-bonded magnets. The polymer (such as epoxy)-bonded magnets can be produced with close tolerances off tool, with little or no finishing required. CMS Magnetics supplies polymer-bonded neodymium permanent magnets made by both compression moulding and injection moulding. The sintered magnets usually require some finishing process in order to hold close mechanical tolerances. The sintered magnets, however, provide better magnetic properties than bonded magnets.
Neodymium magnets are the most powerful magnet developed so far and due to this reason and its affordable cost, neodymium magnets are revolutionizing magnetic products across all the industries. To give an idea of their strength, the neodymium magnets are between seven and fourteen times stronger than ceramic magnets so they are sometimes called super strong or powerful magnets. CMS magnetics, Inc. markets top quality neodymium magnets range from grade N27 up to N52 on the market and operating an online store www.Magnet4Sale.com with the most popular grades and dimensions.
Grade N52 neodymium magnets are the most powerful magnets so far and one grade N52 magnet measuring only ½” can have a pull force of 32 lbs.! Our shop carries a variety of these powerful magnets for sale to fit many different applications.
Neodymium magnets can be fabricated into many shapes and types:
- disc magnets
- ring magnets
- cube magnets
- wedge magnets
- sphere magnets
- counter sunk hole disc magnets
- adhesive neodymium magnets
At Magnet4Sale.com, we also sell custom neodymium magnets and custom magnetic assemblies so we can help you find the best fit for your project specifications.
Neodymium Magnets in Action
Today, no matter where you go, you can always find neodymium magnets in action. In your home, refrigerator magnets, ear buds, jewelry cases and cell phones use this powerful magnet as a tool. Magnets are found in iPads, high end speaker systems, toys and hybrid cars. Neodymium magnets are extensively employed in big industry applications as well. From magnetic separators, lifters, sweepers and fishing systems to switches, precision-guided missiles and wind turbines. Since their invention in 1982, neodymium magnets are rapidly replacing the old and weak technology of ceramic magnets and incorporating their use into daily life.
A little Strong Magnet Knowledge that can help in the selection of your magnets.
- At CMS Magnetics & Magnets For Sale we sell magnets to the hobbyist and to industry with no minimum purchase. We get it to you FAST. CMS Magnetics & Magnets For Sale is rated A+ by the BBB. Our Customer Service people will help you over the phone if you have only a small idea what you need and gladly take your order right there over the phone. They do not work on commission, they really like to help people get it right and are some really nice people. Really! Or you can order on the website.
- A larger magnet of the same material and grade (think strength) will be stronger.
- In order of strength the strongest magnetic material first: Neodymium, Samarium Cobalt, Ceramic, AlNiCo.
- Ceramic magnets are the household magnets or the ones you probably played with as a child.
- If you have 2 magnets that are attracted to each other (stuck together) and you didn’t say “wow how am I ever going to get these separated?” They were not Neodymium. We can show you how to separate them.
- The least strong grade of neodymium (N32) is much stronger than the strongest ceramic magnets.
- Neodymium loses all of its magnetic strength at about 175o Fahrenheit.
- Neodymium corrodes in the weather (6 months) in the elements and it is a mess.
- Samarium Cobalt (SmCo) is a little more expensive and a little less strong but is a great substitute in the above conditions (#6 & #7).
- Do not let your children under about the age of 10 play with Neodymium magnets larger than 1 “ in diameter. They will get pinched. If they play with 2 magnets much larger than that they may get a finger broken. When I started working at CMS I almost got my finger broken by 2 21/2 “ magnets slamming together with my finger between them. Do not place these magnets into orifices of the body. Swallowing 2 small neodymium magnets will cause them to attract to each other along the digestive tract very possibly pinching inner linings and may puncture stomach or intestinal linings (NO JOKE HERE!)
- Most small scale hobbies will do OK with Ceramic magnets however, a refrigerator magnet or tea towel with a small neodymium magnet in it will NOT slide down the refrigerator.
- It is not advised that you make a kitchen knife Holder using a ceramic magnet, eventually someone will get hurt. Use Neodymium.
- All magnets are somewhat brittle. Treat a 1/8th in thick neodymium disc like fine china and it will last a lifetime. A neodymium Disc ½ inch thick is much stronger and the light hand is really not needed but it may still chip.