Magnetic ratings

Printer friendly view			Energy product		Remanence		rev. Temp.- coeff.	Coercivity				rev. Temp.- coeff.	Max. operating temp.	Density
Printer friendly view			(B*H)_max.		B_r		of B_r	H_cB	H_cB	H_cJ	H_cJ	of H_cJ

Rare earth magnets ¹⁾			kJ/m³ (typ.)	kJ/m³ (min.)	mT (typ.)	mT (min.)	ca. %/K	kA/m (typ.)	kA/m (min.)	kA/m (typ.)	kA/m (min.)	approx. %/K	approx. °C	approx. g/cm³
	SmCo₅ 143/143	anisotropic	151	143	920	900	-0,045 ²⁾	700	680	1600	1433	-0,28 ²⁾	250 ³⁾	8,3
	SmCo₅ 160/143	anisotropic	167	160	940	920	-0,045 ²⁾	730	710	1600	1433	-0,28 ²⁾	250 ³⁾	8,3
	Sm₂Co₁₇ 180/160 w	anisotropic	200	180	1040	980	-0,032 ²⁾	750	700	1800	1600	-0,19 ²⁾	350 ³⁾	8,3
	Sm₂Co₁₇ 195/160 h	anisotropic	220	195	1100	1040	-0,032 ²⁾	800	720	1800	1600	-0,19 ²⁾	350 ³⁾	8,3
	NdFeB 180/250 w ⁴⁾	anisotropic	210	180	1050	1000	-0,080 ²⁾	790	720	2800	2500	-0,50 ²⁾	220 ³⁾	7,6
	NdFeB 200/220 w ⁴⁾	anisotropic	230	200	1110	1050	-0,080 ²⁾	850	790	2500	2200	-0,50 ²⁾	190 ³⁾	7,6
	NdFeB 230/175 w ⁴⁾	anisotropic	260	230	1190	1130	-0,090 ²⁾	890	840	1900	1750	-0,60 ²⁾	160 ³⁾	7,6
	NdFeB 250/125 w ⁴⁾	anisotropic	280	250	1230	1170	-0,100 ²⁾	890	840	1400	1250	-0,60 ²⁾	130 ³⁾	7,5
	NdFeB 210/250 h ⁴⁾	anisotropic	240	210	1110	1050	-0,080 ²⁾	860	800	2800	2500	-0,50 ²⁾	220 ³⁾	7,6
	NdFeB 230/220 h ⁴⁾	anisotropic	255	230	1160	1100	-0,080 ²⁾	890	840	2500	2200	-0,50 ²⁾	190 ³⁾	7,6
	NdFeB 250/175 h ⁴⁾	anisotropic	295	250	1240	1180	-0,090 ²⁾	920	860	1900	1750	-0,60 ²⁾	160 ³⁾	7,6
	NdFeB 270/125 h ⁴⁾	anisotropic	300	270	1280	1220	-0,100 ²⁾	920	870	1400	1250	-0,60 ²⁾	130 ³⁾	7,5
	NdFeB 300/125 h ⁴⁾	anisotropic	330	300	1320	1260	-0,100 ²⁾	950	900	1400	1250	-0,60 ²⁾	130 ³⁾	7,5
	NdFeB 342/135 h ⁴⁾	anisotropic	366	342	1380	1320	-0,110 ²⁾	1000	955	1500	1353	-0,60 ²⁾	120 ³⁾	7,5

w: axially pressed in the die
h: highly residual materials - isostatically pressed and separated or diametrically pressed in the die
¹⁾ All values were determined with standard samples according to IEC 60404-5. With unusual geometries, especially with thin walls or narrow pole pitches, deviations from the material data can occur.
²⁾ In the temperature range from 20 °C to 100 °C.
³⁾ The max. operating temperature depends on the magnet dimension and the specific application. Please contact our application engineering for more information.
⁴⁾ Licensor Hitachi Metals Ltd.

Term definition

Samarium-Cobalt (SmCo):

Used as alloy (SmCo₅ or Sm₂Co₁₇) for the preparation of permanent magnets. These magnets have high coercive field strength, allowing temperatures of use of up to 350°C. Samarium belongs to the rare earth elements.

Neodymium-Iron-Boron (NdFeB)

Magnets made of an NdFeB alloy can reach the highest remanences. Suitable alloys can be used for temperatures of more than 200°C. Neodymium belongs to the rare earth elements.

Isotropic:

Description that a property is independent of the direction. For a magnet, this means that all molecular magnets (the smallest magnetic particles) have different distributions. This apparent chaos balances the positions of all the molecular magnets, thus also balancing their effect toward the exterior. If a magnet prepared under isotropic conditions is magnetized, only the molecular magnets already oriented in the direction of magnetization will be magnetized. This is why magnets of the same material prepared under isotropic conditions are weaker than magnets prepared under anisotropic conditions.

Anisotropic:

The opposite of isotropic describes that a property depends on the direction. For a magnet, this means that all molecular magnets have the same orientation. This can be achieved by preferential orientation of the base material. The magnetic values of the magnets prepared under anisotropic conditions are clearly higher than those of the magnets prepared under isotropic conditions.

Energy product (B*H)_max:

The final values B_r (remanence), H_c (coercive field strength) and (B*H)_max. (energy product) are the most important magnetic properties of a permanent magnet. The greatest possible energy product (B*H)_max. describes the highest energy density that can be achieved with a material. In general, the following applies: The higher the energy density, the smaller the magnetic volume (V) required for a certain task under otherwise identical conditions.

Remanence B_r:

Remanence is understood as meaning the remaining magnetism in a particle, after removing the magnetizing field. The term remanence is the associated remaining flux density. The remaining magnetism is formed by a previously used magnetic field, such as that of an electrified coil giving the particle its own magnetic field by virtue of induction.

Rev. temp. coeff:

Stands for the reversible temperature coefficient and represents the relative change in a physical property as a function of a change in temperature by one Kelvin.

Coercivity:

Stands for the magnetic field strength required to completely demagnetize ferromagnets. A high coercive field strength means that a magnet exhibits high stability against demagnetization. Please note that the coercive field strength is highly temperature-dependent.

Max. operating temp.:

Denotes the maximum temperature at which the magnet can still be used. It is far below the Curie temperature. Please note that the maximum operating temperature is a function of the magnet geometry and the opposite fields occurring in use. This means that the values stated in the data sheets are only guide values.

Density:

The density of a body is the relationship between the mass and the volume and describes whether a body is relatively light or heavy.

Magnete-Tag-Cloud

Magnetic ratings

Term definition