The grade, or “N rating” of the magnet refers to the Maximum Energy Product of the material that the magnet is made from. It refers to the maximum strength that the material can be magnetized to. The grade of neodymium magnets is generally measured in units millions of Gauss Oersted (MGOe). A magnet of grade N42 has a Maximum Energy Product of 42 MGOe. Generally speaking, the higher the grade, the stronger the magnet.
Neodymium magnets are a member of the rare earth magnet family. 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 magnets and are the strongest permanent magnets in the world.
All of the pull force values we specify have been tested in our laboratory. We test these magnets in two different configurations.Case 1 is the maximum pull force generated between a single magnet and a thick, ground, flat steel plate. Case 2 is the maximum pull force generated with a single magnet sandwiched between two thick, ground,flat steel plates. Case 3 is the maximum pull force generated on a magnet attracted to another magnet of the same type.The values are an average value for five samples of each magnet. A digital force gauge records the tensile force on the magnet. The plates are pulled apart until the magnet disconnects from one of the plates.The peak value is recorded as the “pull force”. If using steel that is thinner, coated, or has an uneven or rusty surface, the effective pull force may be different than recorded in our lab.
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 (or Tesla). Pull Force Testers are used to test the holding force of a magnet that is in contact with a flat steel plate. Pull forces are measured in pounds (or kilograms).
Ferromagnetic materials are strongly attracted by a magnetic
force. The elements iron (Fe), nickel (Ni), and cobalt
(Co) are the most commonly available elements. Many types of steel are
ferromagnetic because of the iron content. Steel is an alloy of iron, carbon and other elements.
Neodymium (more precisely Neodymium-Iron-Boron) magnets are the strongest permanent magnets in the world.Neodymium magnets are a member of the Rare Earth magnet family and are
the most powerful permanent magnets in the world. They are also
referred to as NdFeB magnets, or NIB, because they are composed mainly
of Neodymium (Nd), Iron (Fe) and Boron (B). They are a relatively new
invention and have only recently become affordable for everyday use.
There are several simple methods that can be used to identify the (Scientific) North and South poles of neodymium magnets.
1)
The easiest way is to use another magnet that is already marked. The
North pole of the marked magnet will be attracted to the South pole of
the unmarked magnet.
2) If you take an even number of magnets and
pinch a string in the middle of the stack and dangle the magnets so they
can freely rotate on the string, the North pole of the magnets will
eventually settle pointing North. This actually contradicts the
“opposites attract” rule of magnetism, but the naming convention of the
poles is a carry over from the old days when the poles were called the
“North-seeking” and “South-seeking” poles. These were shortened over
time to the “North” and “South” poles that we know them as.
3) If you have a compass handy, the end of the needle that
normally points North will be attracted to the South pole of the neodymium magnet.
Ambient temperature: since sintered NdFeB magnet has negative temperature coefficients of remanence Br and coercivity Hc, the temperature will demagnetize the magnet to some extent, reversibly or irreversibly. The loss is also recoverable or irrecoverable.
All magnets have points, or poles, where their magnetic strength is concentrated.Those points are called poles. We label them north and
south because suspended magnets orient along north-south planes. On different magnets, like poles repel each other, opposite poles
attract.
Modern permanent magnets are made of special alloys that have been found through research to create increasingly better magnets. The most common families of magnet materials today are ones made out of Aluminum-Nickel-Cobalt (Alnicos),Strontium-Iron (Ferrites, also known as Ceramics), Neodymium-Iron-Boron (Neo magnets, sometimes referred to as “super magnets”), and Samarium-Cobalt. (The Samarium-Cobalt and Neodymium-Iron-Boron families are collectively known as the Rare Earths.)