NdFeB magnet grade standard
The first step, let's learn more about the grade of NdFeB magnet, which is actually the grade of the magnet. The higher the grade, the stronger the performance, the greater the magnetism, and the higher the price.
Example: N35 grade, the letter N is the English abbreviation of NdFeB, and 35 is the maximum magnetic energy product. There is no letter behind the number, which means the maximum working temperature is 80 degrees Celsius. N42SH grade, the letter N is the English abbreviation of NdFeB, and 42 is the maximum magnetic energy product. SH is a high temperature resistant grade, which means that the maximum working temperature is 150 degrees Celsius.
N grade, the maximum working temperature is 80 degrees Celsius;
M grade, the maximum working temperature is 100 degrees Celsius;
H grade, the maximum working temperature is 120 degrees Celsius;
SH grade, the maximum working temperature is 150 degrees Celsius;
SH-T grade, the maximum working temperature is 160 degrees Celsius;
UH grade, the maximum working temperature is 180 degrees Celsius;
UH-T grade, the maximum working temperature is 190 degrees Celsius;
EH grade, the maximum working temperature is 200 degrees Celsius;
AH grade, the maximum working temperature is 220 degrees Celsius.
Performance list of NdFeB magnets
Performance parameters of NdFeB magnets
Remanence Br: After the permanent magnet is magnetized to technical saturation and the external magnetic field is removed, the retained Br is called the residual magnetic induction.
Coercive force Hc: To reduce the B of the permanent magnet magnetized to technical saturation to zero, the required reverse magnetic field strength is called the magnetic induction coercive force, referred to as the coercive force.
Magnetic energy product BH: It represents the magnetic energy density established by the magnet in the air gap space (the space between the two magnetic poles of the magnet), that is, the static magnetic energy per unit volume of the air gap. Since this energy is equal to the product of Bm and Hm of the magnet, it is called the magnetic energy product.
Remanence Br: Comparing a magnet to a sponge, the remanence is like a sponge absorbing water and saturating it. At this time, the magnetic value of the magnet displayed;
Coercive force Hc: The water in the sponge is absorbed to the maximum, and then the water is pressed out until there is no water in the sponge. The pressure used is like the coercive force;
Magnetic energy product BH: The sponge is saturated with water, the total amount of water inside.
The strong magnetic force generally depends on Br (remanent magnetism), and the long-lasting magnetic force depends on Hc (coercive force).
But special attention must be paid, when the magnet grade and size are determined, the values of Br and Hc are generally fixed. If it is necessary to change the two values, it is also a proportional change. Just like a sponge, the larger and smaller pores of the sponge will affect the water stored in it, and the difficulty of squeezing out the water will also change.