D25 x d7,5/4,5 x 5 / N38 - NdFeB (neodymium) magnet
- External diameter
- 25 [mm]
- Aperture diameter for head of a screw
- 7,5 [mm]
- Internal diameter
- 4,5 [mm]
- 5 [mm]
- magnetizing direction along dimension
- 5 [mm]
- Maximal hoisting capacity
- 8 [kg]
- Magnetic field in geometrical center of the magnetic pole surface
- 0,3 [T]
- Maximum working temperature
- 80 °[C]
- Nickel (NiCuNi)
- Magnetic moment
- 23900 [nWb]x[m]
- 17,4 [g]
Direction of magnetization along the height means that one circular surface of a magnet makes the N-pole, while the other – opposite – circular surface refers to the S-pole.
The pull force was measured by using metal sheet 10 [mm] thick, acting with perpendicular detaching force. The air gap comprised between the metal sheet and a magnet causes reduction in the pull force.
For flat magnets and magnets mounted in the open magnetic circuit working temperature may be insignificantly lower. For high magnets and magnets mounted in the closed magnetic circuit working temperature equals max. working temperature for a given material. Curie’s temperature is ~ 310°[C]. Temperature coefficient of remanence TK(Br: approx. ~0,12 %/°[C]. Temperature coefficient of coercivity TK(HcJ): approx. -0,6 %/°[C].
All the numbers quoted were obtained as a result of tests with one specific item in a room temperature and are intended to serve for comparison of practical magnetic properties of magnets offered by the shop.
Magnetic properties of material grade N38
|remanence Br||1,21 - 1,25 [T]|
|coercivity HcB||min. 899 [kA/m]|
|coercivity HcJ||min. 955 [kA/m]|
|energy product (BH)max||286 - 302 [kJ/m3]|
|Magnetic properties of a particular material, together with its shape, volume, max. working temperature and direction of magnetization have influence on practical magnetic properties of a magnet.|
|As an example, you will find attached a graph of a course of the II quadrant of magnetic hysteresis loop for a material grade N38.|
|Vickers’ hardness (HV)||~600 [kg/mm2]|
|resistivity||~144 [uOhm x cm]|