Permanent magnetsFerrite, ndFeB, alniCo & smCo magnets

Attractive technology.

Permanent magnets

BLS Magnet [2] Permanent magnets BLS Magnet [3] Permanent magnets

Many technological advances only became possible after the development of

extremely powerful permanent magnets in various shapes and sizes.

Today, magnetic materials have very different magnetic and mechanical properties,

and the four families of permanent magnets can thus be used in a very wide range

of applications. BLS Magnet has a very large stock of permanent magnet in many

shapes and sizes and also offers tailor-made magnets.

Ferrite magnetsPage 4

neODYmium magnetsPage 6

alniCO magnetsPage 8

samarium COBalt magnetsPage 10

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aPPliCatiOnsPage 15

glOssarY OF termsPage 16

saFetY warningsPage 19

magnetizatiOn DireCtiOnPage 12

ChOOsing magnet materialsPage 14

Since 1987, BLS Magnet designs and manufactures innovative magnetic com-ponents, equipment and

materials...

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Ferrite

BLS Magnet [4] Permanent magnets BLS Magnet [5] Permanent magnets

Ferrite magnetsAvailable since the mid-1950s, ferrite magnets are used in many applications due to their relatively

low manufacturing cost.

Ferrite magnets are made of more than 80% of iron oxide and contain strontium or barium depen-

ding on the desired magnetic properties and are available in isotropic and anisotropic versions.

The machining of this type of magnet requires diamond tools. Relatively brittle, this material is very

resistant to corrosion, acids and solvents, and its magnetic properties are maintained under widely

varying temperatures (-40 to + 250°C).

Grade Remanence Remanence Coercive force Coercive force Intrinsic coer-cive force

Intrinsic coer-cive force

Energy product (B-H)max

Energy product (B-H)max

Br (Kg) Br (mT) -HcB (kOe) -HcB (kA/m) -HcJ (kOe) -HcJ (kA/m) (MGOe) (Kj/m3)

min typ min typ min typ min typ min typ min typ min typ min typ

F 1 2.10 2.2 210 220 1.6 1.7 130 135 2.6 2.8 210 220 0.9 0.96 7.2 7.6

F 3 3.50 3.7 350 370 1.9 2.2 155 175 2 2.3 160 180 3 3.2 24 25.5

F 5 3.90 4 390 400 1.8 2 145 160 1.9 2.1 150 165 3.5 3.7 28 29.5

F 7 3.50 3.7 350 370 2.6 3.1 210 245 2.8 3.2 220 255 3.1 3.2 24.5 25.5

F 8 3.80 3.9 380 390 3 3.2 240 255 3.1 3.3 245 260 3.3 3.49 26 27.8

F 9 3.85 3.95 385 395 3.4 3.5 270 280 3.5 3.6 280 290 3.5 3.6 28 29

Grade Reversible temperature coefficient,

Br

Reversible temperature coefficient,

Br

Density Permeability Intensity of magnetiza-tion field

Intensity of magnetiza-tion field

Thermal expansion coefficient

Max working temperature

Curie tem-perature

%/°C %/°C g/cm3 μ rev kOe kA/m 10/°C °C °C

F 1 - 0.2 + 0.4 4.9 1.05 -1.3 - - 9 - 15 250 450

F 3 - 0.2 + 0.4 4.8 1.05 -1.3 > 20 > 800 9 - 15 250 450

F 5 - 0.2 + 0.4 4.9 1.05 -1.3 > 20 > 800 9 - 15 250 450

F 7 - 0.2 + 0.4 4.7 1.05 -1.3 > 20 > 800 9 - 15 250 450

F 8 - 0.2 + 0.4 4.8 1.05 -1.3 > 20 > 800 9 - 15 250 450

F 9 - 0.2 + 0.4 4.8 1.05 -1.3 > 20 > 800 9 - 15 250 450

The demagnetization curves for each grade are available upon request.

NdF

eB

BLS Magnet [6] Permanent magnets BLS Magnet [7] Permanent magnets

nDFeB magnetsGrade Remanence Remanence Coercive force Coercive force Intrinsic

coercive force

Intrinsic coercive

force

Energy product (B-H)max

Energy product (B-H)max

Max working temperature

Br (kG) Br (mT) -HcB (kOe) -HcB (kA/m) -HcJ (kOe) -HcJ (kA/m) (MGOe) (Kj/m3) °C

min typ min typ min typ min typ min typ min typ

N 35 11.7 12.2 1170 1220 10.5 11.2 836 891 ≥ 12 ≥ 955 33 35 263 279 ≤ 80

N 38 12.2 12.6 1220 1260 10.5 11.2 836 891 ≥ 12 ≥ 955 35 38 279 302 ≤ 80

N 40 12.6 13 1260 1300 10.5 11.2 836 891 ≥ 12 ≥ 955 38 40 302 318 ≤ 80

N 42 13 13.3 1300 1330 10.5 11.2 836 891 ≥ 12 ≥ 955 40 42 318 334 ≤ 80

N 45 13.3 13.7 1330 1370 10.5 11.2 836 891 ≥ 12 ≥ 955 42 45 334 358 ≤ 80

N 48 13.7 14.1 1370 1410 10.2 10.8 812 859 ≥ 11 ≥ 875 45 48 358 382 ≤ 70

N 50 14.1 14.4 1410 1440 10.8 10.8 812 859 ≥ 11 ≥ 875 50 50 382 400 ≤ 70

N 52 14.4 14.7 1440 1470 10.8 10.8 812 859 ≥ 11 ≥ 875 53 53 400 415 ≤ 70

N 33 M 11.4 11.7 1140 1170 10.2 10.8 812 859 ≥ 14 ≥ 1114 30 33 239 263 ≤ 100

N 35 M 11.7 12.2 1170 1220 10.5 11.2 836 891 ≥ 14 ≥ 1114 33 35 263 279 ≤ 100

N 38 M 12.2 12.6 1220 1260 10.8 11.5 859 915 ≥ 14 ≥ 1114 35 38 279 302 ≤ 100

N 40 M 12.6 13 1260 1300 10.8 11.5 859 915 ≥ 14 ≥ 1114 38 40 302 318 ≤ 100

N 42 M 13 13.3 1300 1330 10.8 11.5 859 915 ≥ 14 ≥ 1114 40 42 318 334 ≤ 100

N 45 M 13.3 13.7 1330 1370 10.8 11.5 859 915 ≥ 14 ≥ 1114 42 45 334 358 ≤ 100

N 48 M 13.7 14.1 1370 1410 10.8 13 859 1035 ≥ 14 ≥ 1114 45 48 355 385 ≤ 90

N 50 M 14 14.4 1400 1440 10.8 13 859 1035 ≥ 14 ≥ 1114 47 50 370 400 ≤ 90

N 30 H 10.8 11.4 1080 1140 9.8 10.2 780 812 ≥ 17 ≥ 1353 28 30 223 239 ≤ 120

N 33 H 11.4 11.7 1140 1170 10.2 11 812 875 ≥ 17 ≥ 1353 30 33 239 263 ≤ 120

N 35 H 11.7 12.2 1170 1220 10.5 11.2 836 891 ≥ 17 ≥ 1353 33 35 263 279 ≤ 120

N 38 H 12.2 12.6 1220 1260 10.8 11.5 859 915 ≥ 17 ≥ 1353 35 38 279 302 ≤ 120

N 40 H 12.6 13 1260 1300 10.8 11.5 859 915 ≥ 17 ≥ 1353 38 40 302 318 ≤ 120

N 42 H 13 13.3 1300 1330 10.8 11.5 859 915 ≥ 17 ≥ 1353 40 42 318 334 ≤ 120

N 45 H 13.3 13.7 1330 1370 10.8 12.3 859 980 ≥ 17 ≥ 1353 42 45 334 358 ≤ 120

N 30 SH 10.8 11.4 1080 1140 98 10.2 780 812 ≥ 20 ≥ 1592 28 30 223 239 ≤ 150

N 33 SH 11.4 11.7 1140 1170 10.2 11 812 875 ≥ 20 ≥ 1592 30 33 239 263 ≤ 150

N 35 SH 11.7 12.2 1170 1220 10.5 11.2 836 891 ≥ 20 ≥ 1592 33 35 263 279 ≤ 150

N 38 SH 12.2 12.6 1220 1260 10.8 11.5 859 915 ≥ 20 ≥ 1592 35 38 279 302 ≤ 150

N 40 SH 12.6 13 1260 1300 10.8 11.5 859 915 ≥ 20 ≥ 1592 38 40 302 318 ≤ 150

N 42 SH 13 13.3 1300 1330 10.8 11.5 859 915 ≥ 20 ≥ 1592 40 42 318 334 ≤ 150

N 28 UH 10.4 10.8 1040 1080 9.8 10.2 780 812 ≥ 25 ≥ 1989 25 28 199 223 ≤ 160

N 30 UH 10.8 11.4 1080 1140 100 10.6 796 844 ≥ 25 ≥ 1989 28 30 223 239 ≤ 160

N 33 UH 11.4 11.7 1140 1170 10.2 11 812 875 ≥ 25 ≥ 1989 30 33 239 263 ≤ 160

N 35 UH 11.7 12.2 1170 1220 10.5 11.2 836 891 ≥ 25 ≥ 1989 33 35 263 279 ≤ 160

N 38 UH 12.2 12.6 1220 1260 10.5 11.5 836 915 ≥ 25 ≥ 1989 35 38 279 302 ≤ 160

N 28 EH 10.4 10.8 1040 1080 9.8 10.2 780 812 ≥ 30 ≥ 2387 25 28 199 223 ≤ 180

N 30 EH 10.8 11.4 1080 1140 10 10.6 796 844 ≥ 30 ≥ 2387 28 30 223 239 ≤ 180

N 33 EH 11.4 11.7 1140 1170 10.2 11 812 875 ≥ 30 ≥ 2387 30 33 239 263 ≤ 180

N 35 EH 11.7 12.2 1170 1220 10.5 11.5 836 915 ≥ 30 ≥ 2387 33 35 263 279 ≤ 180

N 38 EH 12.2 12.6 1220 1260 - - 836 915 ≥ 30 ≥ 2387 - - 279 303 ≤ 180

N28 AH 10.4 10.8 1040 1080 - - 780 812 ≥ 30 ≥ 2387 - - 203 218 ≤ 220

The first neodymium magnets were industrially available in the 1970’s.

These rare earth magnets are the strongest magnets currently avai-

lable. These magnets contain «rare earth» (Nd2F14B), metals with

similar properties of lanthanides and highly volatile prices. Their manu-

facturing process is very complex and different raw materials must be

mixed under specific conditions (vacuum or inert gas).

More sensitive to oxidation than other magnetic materials, neodymium

magnets are in most cases provided with surface treatment, mainly

zinc, nickel or epoxy. Therefore, neodymium magnets are generally

more expensive than other types of magnets.

Due to their excellent magnetic properties, NdFeB magnets offer

great flexibility of use in replacing traditional materials such as ferrite

magnets, alnico and samarium cobalt with greater efficiency and more

compact format. These magnets are generally used for applications

requiring a strong magnetic field in a small space. For comparison, the

magnets require up to five times less space than ferrite magnets, at

equivalent magnetic strength. Nevertheless, this type of magnets has

a lower maximum temperature of use, up to 180°C for some grades.

NdFeB magnets can have maximum energy product of up to 53 MGOe

and they possess a high remanence and coercivity. They are available

in a wide range of colors, sizes and shapes to suit specific applications.

Grade Reversible temperature

coefficient, Br

Reversible temperature

coefficient, Br

Density Permeability Intensity of magnetization

field

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field

Curie tempera-ture

%/°C %/°C g/cm3 μ rev kOe kA/m °C

N 35-33 UH - 0.12 - 0.6 7.35 1.1 30 2400 310 - 340

The demagnetization curves for each grade are available upon request.

AlNiCo

BLS Magnet [8] Permanent magnets BLS Magnet [9] Permanent magnets

alniCO magnetsAlnico magnets were developed in the early 1930’s. First used in military electronic applications

during the Second World War, this type of magnet then spread very quickly for civilian purposes.

Made of an alloy of aluminum, nickel, cobalt and iron, alnico magnets have a reasonable cost

compared to other materials such as neodymium magnets for example. With a maximum operating

temperature of 500°C, alnico magnets are particularly suitable for specific applications in the ae-

rospace and automotive (sensors). However, alnico magnets are very sensitive to demagnetization

factors and therefore must comply with certain shapes and length/diameter ratios to prevent this

phenomenon.

Grade Remanence Remanence Coercive force Coercive force Intrinsic coer-cive force

Intrinsic coer-cive force

Energy product (B-H)max

Energy product (B-H)max

Br (Kg) Br (mT) -HcB (kOe) -HcB (kA/m) -HcJ (kOe) -HcJ (kA/m) (MGOe) (Kj/m3)

A 260 6.1 610 1.3 100 1.38 110 2.4 19

A 450 8.5 850 1.3 100 1.38 110 2.4 36

A 500 11.6 1160 0.6 18 0.63 50 4.4 35

Grade Reversible temperature

coefficient, Br

Density Permeability Intensity of magnetization

field

Intensity of magnetization

field

Max working temperature

Curie tempera-ture

%/°C g/cm3 μ rev kOe kA/m °C °C

A 260 -0.02 7.2 3 800 64 500 860

A 450 -0.02 7.2 3 800 64 500 850

A 500 -0.02 7.2 4 500 40 500 860

The demagnetization curves for each grade are available upon request.

BLS Magnet [10] Permanent magnets BLS Magnet [11] Permanent magnets

samarium COBalt magnetsSamarium cobalt magnets (Sm-Co) were the first magnets to use rare earths and have been com-

mercialized in the 1960’s. Due to its high-performance magnetic properties, this type of magnet

is still used in a large number of high-end applications. Their energy product can reach 33 MGOe

(upon request for specific applications) and the magnets are highly resistant to corrosion, and

therefore ideal for medical applications.

The SmCo magnets can be used up to 300°C and are relatively insensitive to demagnetization

factors and therefore correspond perfectly to special engine applications. However, it is not recom-

mended to use these magnets as a structural component in an assembly because these magnets

tend to flake off.

Grade Remanence Remanence Coercive force Coercive force Intrinsic coercive force

Intrinsic coercive force

Energy product (B-H)max

Energy product (B-H)max

Br (Kg) Br (mT) -HcB (kOe) -HcB (kA/m) -HcJ (kOe) -HcJ (kA/m) (MGOe) (Kj/m3)

min typ min typ min typ min typ min typ min typ min typ min typ

S 18 8.5 8.9 850 890 7.8 8.4 620 670 13.8 15.1 1100 1200 17.6 18.8 140 150

S 22 9 9.5 920 950 7.9 8.8 630 700 10 13 800 1035 18.8 22 150 175

S 24 10 10.5 1000 1050 8.5 9.4 680 750 15 18.8 1195 1500 23.9 25.8 190 205

Grade Reversible temperature

coefficient, Br

Reversible temperature

coefficient, Br

Density Permeability Intensity of magnetization

field

Intensity of magnetization

field

Tempéra-ture max. de

fonctionnement

Curie tempera-ture

%/°C %/°C g/cm3 μ rev kOe kA/m °C °C

S 18 -0.05 -0.3 8.1 1.05 25 2000 250 720

S 22 -0.05 -0.3 8.1 1.05 25 2000 250 720

S 24 -0.03 -0.2 8.3 1.05 50 4000 300 800

SmCo The demagnetization curves for each grade are available upon request.

BLS Magnet [12] Permanent magnets BLS Magnet [13] Permanent magnets

magnetizatiOn DireCtiOn

Shapes Magnetization dir. 1 2 3 4 5 6 Applications

Axially oriented • • • • • • Speakers, pot magnets, magnetic fixing systems.

Multi-pole axial orientation • • • • Motors, clutches, brakes,

Hall effect sensors.

Radially oriented • • Lifting magnets, fastening systems, bearings.

Oriented through diameter • • • • • • Motors, pumps.

Multi-pole orientation segments on one face • • Electromagnetic clutches,

brakes, fastening systems, Hall effect sensors.

Multi-pole orientation segments on outside diameter • • Dynamos, motors, clutches,

brakes, Hall effect sensors.

1: Isotropic ferrite 2: Anisotropic ferrite3: Sintered neodymium4: Isotropic neodymium5: Samarium cobalt6: Alnico

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Shapes Magnetization dir. 1 2 3 4 5 6 Applications

Multi-pole orientation on inside diameter • • Motors, clutches, brakes,

Hall effect sensors.

Multi-pole lateral orientation • • Brakes, fastening systems,

contact with inert gases.

Radially oriented • • • Motors, clutches

Diametrically oriented • • • • • • Motors, clutches.

1: Isotropic ferrite 2: Anisotropic ferrite3: Sintered neodymium4: Isotropic neodymium5: Samarium cobalt6: Alnico

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ChOOsing magnet materials

Comparison table of different magnet materials

Material Cost Max intensi-ty (Gauss)

T°C max Corrosion resis-tance

Magnetic prop-erties

AlNiCo €€ 9000 550°C

Ferrite € 3500 350°C

SmCo €€€€ 32000 375°C

NdFeB €€€ 50000 200°C

CoatingsDepending on the application, BLS Magnet magnets can provide you with the suitable coating (Zn, Ni, Sn, Epoxy, etc.).

BLS Magnet [14] Permanent magnets

Application

Manufacturing process

Material(ferrite, NdFeb, Smco, Alnico)

Coating

Pull force Temperature

Cost

Magnet gradeMagnetization

direction

Dimensions

Weight

Magnetic materials (ferrite, NdFeB, SmCo and

AlNiCo) have very different magnetic properties.

In addition, many other factors have a significant

direct effect on the magnetic force of the magnets

and their fields of applications such as:

• Manufacturing process

• Magnet grade

• Magnetization direction

• Coating.

It is therefore very important to take into account all

of these factors when selecting a magnet ain order

to ensure that it meets your specific application.

BLS Magnet offers its know-how to simplify this

long and complex process and guaranteeing you

to always get the most suitable solution for your

application.

Automotive industryFrequently used in built-in electronics and in all electric motors as that of windshield wiper blades, the automotive industry uses a wide selection of permanent magnets of very varied materials and shapes.

ElectronicsOnly a few of our everyday electronic devices do not include permanent magnets. From headphones to hard drives and smartphones, magnets are everywhere!

Wind powerPermanent magnets are widely used in permanent magnet generators which are more efficient compared to other energy conversion methods.

Packaging / cosmetics industriesLightweight and unobtrusive, permanents magnets can be used to design innovative, practical and stylish packaging, providing an invisible closure system for example when magnets are hidden within the packaging.

aPPliCatiOns

BLS Magnet [15] Permanent magnets

AIR GAPIt is the space between the magnetic poles of a magnet, which can be filled with any non-magnetic material, such as brass, wood or plastic.

ANISOTROPIC MAGNETA magnet having a preferred direction of magnetic orientation, so that the magnetic characteristics are optimal in a preferred direction.

ANISOTROPyAnisotropy is the property of certain specific physical magnitudes which have different values in certain directions. Magnets are anisotropically manufactured at high magnetic field in a specific direction during the sin-tering process.

BIPOlAR MAGNETMagnet having two poles on the same side.

COERCIvE FIElDWith the value of the coercive field Hc, we can determine the intensity of the magnetic field opposed needed to completely demagnetize a magnet. In other words, the higher its value, the more the magnet will keep its mag-netic capabilities when it will be subject to an opposite field.

CoerCive forCe, HcAlso called coercivity. Hc is the magnetic field required to reduce the in-duction B and the magnetization M to zero. It is measured in oersteds or amps / meter is used to measure the resistance of a magnetic material to its demagnetization.

COERCIvITy Hci OR IhcIt is the resistance of a magnetic material to demagnetization. The value H cancels the magnetic induction and it is measured in oersteds or amps per meter A / m.

Curie temperature, tcThis is the temperature above which ferromagnetic materials become paramagnetic, while losing substantially all of its permanent magnetic properties. It usually depends on the chemical composition of the mag-netic material.

DEMAGNETIzATION CURvEIt corresponds to the second quadrant of the hysteresis loop, generally de-scribing the behavior of the magnetic properties in actual use. Also known as B-H curve. This is the part of the curve of a full hysteresis loop in the second dial which defines the main magnetic properties of a magnet. It describes the change due to the magnetic induction or from the demag-netization remanence value to zero by applying a negative direction field.

DIAMAGNETICMagnetic properties of materials that have lower permeability values to 1 (eg. Silver, copper, water, gold, lead, zinc ...).

ENERGy PRODUCT (Bh) MAxThis is the energy that a magnetic material can provide to an external mag-netic circuit when it operates on an item of its demagnetization curve. It is measured in Megagauss-oersteds, MGOe, or kJ / m³. BHmax represents the maximum energy which can be stored in a magnet. The unit used is the kJ.m³ (kilo joule per cubic meter) or MGOe (Mega Gauss Oersted).

FERROMAGNETICMagnetic property of materials that exhibit superior permeability values of 60 to several thousand times μ0 and exhibits hysteresis phenomena. Ex. (Cobalt, iron, mu-metal, nickel ...).

FlUxThis is the number of “magnetic lines of force”, measured in Gauss or Tesla. These lines can be visualized using iron dust.

FlUx DENSITyMagnetic flux per unit area of a section normal to the direction of flow. Also known as magnetic induction. Measured in Gauss, it is a way of defining the induction field as the force line number per unit area.

GAUSSMeasurement unit of the induction, B, in the Gaussian system. 1 G = 10-4 T; 1 mT = 10 G magnetic flux lines per centimeter square cgs unit flux density equivalent lines per square inch in the English system and Weber per square meter or Tesla in the IS system.

HySTERESISThis is the ability of a magnetic material to keep the magnetic force at the time of being exposed to a demagnetizing force.

HySTERESIS CURvEThis is the closed curve obtained when measuring the induction B or the magnetization M when it is subjected to a magnetic field H which de-scribes a complete circle between the limits defined by the induction or magnetization saturation in the first to the third quadrant.

INTRINSIC COERCIvITyValue of the measured field in oersteds or A / m, which indicates the resis-tance of a material to demagnetization. The maximum value is obtained after leading the magnet towards saturation.

intrinsiC induCtion, BiThis is the magnetic material contribution to the total magnetic induction B. It is the vector difference between the magnetic induction in the material and the magnetic induction that would exist in a vacuum under the same force fields, H.

IRREvERSIBlE lOSSThis corresponds to the irreversible changes that take place when a mag-net is demagnetized partially or completely because of exposure to high or low temperatures, or because of other factors such as external demag-netization fields. When the magnets are magnetized again, these losses are recovered. Defined as partial demagnetization of a magnet caused by external fields or other factors. These losses are only recoverable by remagnetization. Magnets can be stabilized to prevent the change in per-formance caused by irreversible losses.

ISOTROPIC MAGNETA magnet material whose magnetic properties are the same in any di-rection and can be magnetized in any direction without loss of magnetic characteristics.

ISOTROPyA magnet is considered isotropic when its properties are independent of its orientation. The particles are randomly oriented. They have no preferred magnetic orientation, which allows snap in any direction.

MAGNETIC CONSTANTAlso called vacuum permeability or magnetic vacuum permittivity, it is a physical constant. It is symbolized by μ0. μ0 can be seen as the intrinsic magnetic vacuum permeability.

MAGNETIC FIElD STRENGTHIt is the magnetization or demagnetization strength, measured in oersteds. It determines the ability of an electric current or a magnetic material to produce a magnetic field in a certain place.

glOssarY OF terms

BLS Magnet [16] Permanent magnets

MAGNETObject made of a hard magnetic material, that is to say whose residual field and the coercive field are great. This gives it special properties like exercising an attractive force on any ferromagnetic material.

MAGNETIC INDUCTIONIt is the magnetization or demagnetization strength, measured in oersteds, which determines the capacity of an electric current or a magnetic materi-al, to impose a magnetic field on a predetermined point.

MAGNETIC INDUCTION BCommonly called induction, it is a phenomenon which binds the electrical voltage in a conducting loop and the variation of a magnetic field there-through. This voltage is commonly called electromotive force or EMF.

MAGNETIC PERMEABIlITyIs the ability of a material to produce a magnetic field, that is to concentrate the magnetic flux lines and thus to increase the value of magnetic induc-tion. This value of the magnetic induction depends on the environment in which it is produced.

MAGNETIC SUSCEPTIBIlITyMagnetic susceptibility is the ability of a material to react to the action of a magnetic field. The reaction is of two types: the appearance of a mechan-ical force and magnetization of the material.

MAxIMUM TEMPERATUREThis is the maximum exposure temperature that a magnet can withstand without structural changes or imbalances in its properties.

MAxWEllUnit by magnetic flux in the Gaussian measurement system. A Maxwell is equivalent to a magnetic flux line.

NORTH POlEMagnetic pole of a magnet which is attracted to the geographic South Pole of the Earth.

OERSTED OeCGS measurement unit used to describe the magnetizing force. The En-glish system is Ampere / turn by inch and in the IS system, Ampere / turn per meter. The unit of magnetic field strength, H, in the GSM electromag-netic system.

ORIENTATION DIRECTIONThe direction in which an anisotropic magnet should be magnetized to achieve optimal magnetic properties. Also referred to as “axis”, “easy axis”, or “tilt angle”.

PARAMAGNETICMagnetic property of materials which exhibits permeability values close to 1. The absolute permeability μ of diamagnetic and paramagnetic materials is practically equal to that of vacuum (eg .: air, aluminum, magnesium, platinum ...)

permissiveness CoeffiCient, pcThis is a proportion of magnetic induction, Bd, at its demagnetization force, Hd. Also called “load line”, “the operating line slope”, or operating points of the magnet, which is useful in the evaluation of the production of the flux of the magnet in various conditions.

REMANENCE (Br)This is the residual magnetization of the magnet which has been mag-netized to saturation in a closed circuit. Br is calculated by Tesla (T) miniTeslas (mT) or Gauss (G), and corresponds to the magnetic induction in the material after being magnetized to saturation and prepared for its final use. The remanence Br is used to measure the induction or persistent flux density in a magnet after being magnetized. For simplicity, the higher the value, the stronger the magnet. The magnetic flux density is measured in Tesla (T). Gauss (G) is also used, 1Tesla = 10,000 Gauss.

REMANENT FIElDThis is the magnetic field existing in the material in the absence of any current.

residual induCtion, BrThis is the point where the hysteresis loop crosses the B axis at zero mag-netizing force and represents the output of the given magnetic material maximum flux. By definition, this point appears at zero air void and can not be used in magnetic materials.

SOUTH POlEMagnetic pole of a magnet which is attracted to the geographic North Pole of the Earth.

SATURATIONThis is the maximum value of magnetization, which refers to the lowering of the permeability and the increasing magnetization force. This is the flux density with a maximum value of magnetization, the highest magnetic po-larization that a magnet can get. In the case of an inductor, it corresponds to the lowering of the current by inductance. It is the condition in which all the elementary magnetic moments have become oriented in one direction. A ferromagnetic material is saturated when an increase in magnetization force applied produces no increase in induction. The flux density satura-tion for steels is in the range of 16000-20000 Gauss.

SINTERINGIt is the heat treatment at high temperatures, so that the pressed parts have a lower volume and are more dense. For ferrites, the values are approximately 1200°C to 1250°C and rare earths, of 1050°C to 1200°C.

STABIlIzATIONIt is the prior exposure of a magnet to demagnetization forces that may be encountered to prevent irreversible loss in actual use. The demagnetiza-tion influences can be caused by high or low temperatures, or by external magnetic fields.

TEMPERATURE COEFFICIENTThis coefficient describes the changes in magnetic properties depend-ing on temperature change. Usually this value is expressed in % of field change per degree of temperature.

TESlAUnit for the magnetic flux density of 1 Tesla = 10,000 Gauss.

WEBERMagnetic flux unit, Weber = 10-8 Maxwell = 1 Vs. Maxwell = 1 Vs. Prac-tical magnetic flux unit. This is the amount of magnetic flux that will en-courage, when bound to a uniform rate of a single electric circuit during an interval of 1 second in this circuit, an electromotive force of 1 volt.

BLS Magnet [17] Permanent magnets

saFetY warnings

ingestiOnIf swallowed, permanent magnets can settle in the intestine and cause serious complications that may

lead to death.

COntusiOnSome permanent magnets are extremely powerful. If not handled properly, two magnets can collide

abruptly and cause bruises or hematomas. It is essential to wear protective gloves at all times.

PrOjeCtiOn OF Fragments OF magnetsIf mishandled, two magnets can collide and break suddenly which can cause the projection of many

fragments of magnets. Protective eyewear is recommended when handling large magnets.

interFerenCe with CarDiaC equiPmentPermanents magnets may interfere with heart devices such as pacemakers or defibrillators. It is impe-

rative to maintain a safe distance with these devices or people with pacemakers.

Other interFerenCesAs they can generate powerful magnetic fields and large amplitude, some magnets can cause damage

to many electronic devices such as televisions, computers including hard drives. It is recommended to

keep a safe distance from any electronic object.

Fire hazarDThe machining of permanent magnets can generate combustible dust. It is essential to take necessary

measures to prevent the risk of fire, by using appropriate tools.

air FreightIf air-shipped, it is important to place magnets in magnetically shielded containers to avoid interference

with air navigation devices that may cause an accident.

BLS Magnet [18] Permanent magnets BLS Magnet [19] Permanent magnets

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