Technical capabilities

Magnetic characteristics

Each magnet has a characteristic shape due to its materialistic physical features.

Rare earth magnets;
This newcomer to the magnet industry with its high performance of both residual flux density and coercive force superior to all other magnets, allows for its very compact and thin design.

Alnico Magnets;
The most established and widely used magnets. Because of the low coercive force and high flux density, the material needs distance between N and S pole, therefore the shape employs a long and thin design. Usable at a high temperature due to a low temperature coefficient.

Ferrite magnets;
The feature of a relatively low residual flux density, coupled with a high coercive force makes material shape flat. Because of high availability of material, the economical cost is attractive to the magnet designers.

MA magnets;
Since the physical property is located between Alnico and Ferrite magnets, MA magnets features both characteristics and employs a thick and short shape.

Standard Rating Characteristics

Typical Magnets

Type of magnets Rare Earth Ferrite Alnico Magnet
Item Unit Nd-Fe-b Sm-Co Isotropic
Ba-Ferrite		 Anisotropic
Sr-Ferrite
by Dry		 Anisotropic
sr-Ferrite
by wet		 Alnico-5 Alnico-8
Brr kG 12.4 10.5 2.2 3.6 4 12.7 8.8
mT 1,240 1,050 220 360 400 1,270 880
bHc kOe 11.6 8 1.9 3 3.3 0.65 1.47
kA/m 923 636 151 238 262 51 117
Bhmax MGOe 37 24 1 3 3.8 5.3 5.2
kJ/m3 294.5 191 8 23.9 30.2 42.2 41.4
Temperature
characteristic
of Br		 %/℃ -0.12 -0.04 -0.18 -0.18 -0.18 -0.02 -0.01
Curie point ℃ 320 750 460 460 460 850 850
Density g/cm3 7.4 8.3 4.8 4.8 4.9 7.3 7.3

B-H CURVE OF TYPICAL MAGNETS

Rare Earth

Item Unit Nd-Fe-B Sm-Co
Compositon ― Nd2・Fe14・B Sm2Co17
Molding Process ― Imposing magnetic field
on the magnet		 Imposing magnetic field
on the magnet
Residual Flux Density
Br		 mT 1210～1270 970～1020
ｋG 12.1～12.7 9.7～1.02
Coercive Force
bHc		 ｋA/m 867～979 557～836
KOe 10.9～12.3 7～10.5
Intrinsic Coercive Force
iHc		 ｋA/m ＞1353 716～1194
KOe ＞17 9～15
Maximum Energy Product
(BH) max		 kJ/m3 278～310 175～199
MGOe 35～39 22～25
Temperature Coefficent Br %/K -0.12 -0.04
Temperature Coefficent iHc %/K -0.58 -0.03
Curie Point
Tc		 K 593 1093
℃ 320 820
Recoil Relative Magnetic
Permeability μA rec		 ― 1.05 1.05
Density g/cm3 7.4 8.3
Deflecting Strength Mpa 245 118
Kgf/mm2 25 12
Compression Strength MPa 1050 500～519
Kgf/mm2 107 51～53
Tensile Strength MPa 44 36
Kgf/mm2 4.5 3.6
Specific Heat J/(Kg・K） 0.50×103 034×103
cal/g・℃ 0.12 0.08
Vickers Hardness HV 600 550
Thermal Expansion Coefficient
Vertical		 ppm/K 5.5～7.5 8
Thermal Expansion Coefficient
Vertical		 ppm/K -3～0.5 11
JIS ― REFe280/120 RECo160/70
MMPA ― ― ―
Magnetic Field To Be Charged
For Magnetization		 kA/m 2400 1990
KOe 30 25
Electric Resistance nΩ・m 1.3×10-4 0.8～0.9

Ferrite

Item Unit Isotropic Anisotropic by Dry Anisotropic by Wet
Compositon ― BaO・6Fe2O3 SrO・6Fe2O3 SrO・6Fe2O3
Molding Process ― Dry Powder Dry Powder
in Magnetic Field		 Wet Powder
in Magnetic Field
Residual Flux Density
Br		 mT ≧200 310～360 380～400
kG ≧2.0 3.1～3.6 3.8～4.0
Coercive Force
bHc		 ｋA/m 127～159 220～250 230～275
KOe 1.6～2.0 2.8～3.2 2.9～3.5
Intrinsic Coercive Force
iHc		 kA/m 135～167 280～320 235～290
KOe 1.7～2.1 3.5～4.0 3.0～3.7
Maximum Energy Product
(BH) max		 kJ/m3 6.3～9.5 20～24 27～32
MGOe 0.8～1.2 2.5～3.0 3.4～4.1
Temperature Coefficent Br %/K -0.18 -0.18 -0.18
Temperature Coefficent iHc %/K 0.22 0.27～0.42 0.27～0.42
Curie Point
Tc		 K 723 733 733
℃ 450 460 460
Recoil Relative Magnetic
Permeability
μrec		 ― 1.1～1.2 1.1～1.2 1.05～1.1
Density g/cm3 4.8 4.9 4.9
Deflecting Strength Mpa 29～68 49～88 49～88
Kgf/mm2 3～7 5～9 5～9
Compression Strength MPa ＞686 ＞686 ＞686
Kgf/mm2 ＞70 ＞70 ＞70
Tensile Strength MPa 19～49 19～49 19～49
Kgf/mm2 2～5 2～5 2～5
Specific Heat J/(Kg・K） 0.84×103 0.84×103 0.84×103
cal/g・℃ 0.2 0.2 0.2
Vickers Hardness HV 530 530 530
Thermal Expansion Coefficient
Lateral		 ppm/K 9.9 11 13
Thermal Expansion Coefficient
Vertical		 ppm/K 9.9 9 8
JIS ― MPB-8/15D MPS-24/24D MPS-31/24W
MMPA ― CERAMIC-1 CERAMIC-6 CERAMIC-8
Magnetic Field To Be Charged
For Magnetization		 kA/m 800 800 800
KOe 10 10 10
Electric Resistance nΩ・m ＞102 ＞102 ＞102

ALNICO

Item Unit Alnico-5 Alnico-8 Alnico Sinter
Compositon ― 8Al-14Ni-24Co-3Cu-othersFe 7Al-15Ni-34Co-4Cu-othersFe 8Al-14Ni-24Co-3Cu-othersFe
Molding Process ― Casting Casting Wet Powder
in Magnetic Field
Residual Flux Density
Br		 mT 1250～1300 830～900 1150
kG 12.5～13 8.3～9.0 11.5
Coercive Force
bHc		 kA/m 47.7～52.5 110～123 50
KOe 0.60～0.66 1.38～1.55 0.63
Intrinsic Coercive Force
iHc		 kA/m ― ― ―
KOe
Maximum Energy Product
(BH) max		 kJ/mm3 38.2～43.8 38.2～43.0 37
MGOe 4.8～5.5 4.8～5.4 4.6
Temperature Coefficent Br %/K -0.02 -0.02 -0.02
Temperature Coefficent iHc %/K ― ― ―
Curie Point
Tc		 K 1123 1123 1123
℃ 850 850 850
Recoil Relative Magnetic
Permeability
μrec		 ― 3.6 3.6 3.6
Density g/cm3 7.3 7.3 7.1
Deflecting Strength Mpa 73.5 73.5 7.35
Kgf/mm2 7.5 7.5 7.5
Compression Strength MPa ― ― ―
Kgf/mm2
Tensile Strength MPa 37.2 37.2 37.3
Kgf/mm2 3.8 3.8 3.8
Specific Heat J/(Kg・K） ― ― ―
cal/g・℃
Vickers Hardness HV 650 650 650
Thermal Expansion Coefficient
Lateral		 ppm/K 11 11 11
Thermal Expansion Coefficient
Vertical		 ppm/K 11 11 11
JIS ― AlNiCo37/5 AlNiCo38/11 AlNiCo S-34/5
MMPA ― AlNiCO-5 AlNiCO-8 ―
Magnetic Field To Be Charged
For Magnetization		 kA/m 240 640 240
KOe 3.0 8.0 3.0
Electric Resistance nΩ・m 4.7×102 4.7×102 47×102

Others

Item Unit Nd-Fe-B Bond Anisotropic Rubber
Magnet		 Isotropic Rubber
Magnet
Compositon ― Nd2・Fe14・B ― ―
Molding Process ― Compression Injection Rolling Rolling
Residual Flux Density
Br		 mT 640～710 640～710 230 1370
kG 6.4～7.1 6.4～7.1 2.3 1.37
Coercive Force
bHc		 kA/m 570～760 410～620 135 102
KOe 5.7～7.6 4.1～6.2 1.7 1.28
Intrinsic Coercive Force
iHc		 kA/m 370～470 250～400 ― ―
KOe 4.7～5.9 3.1～4.9
Maximum Energy Product
(BH) max		 kJ/m3 60～96 28～60 8.8 4.0
MGOe 7.5～12.0 3.5～7.5 1.1 0.5
Temperature Coefficent Br %/K -0.1～-0.15 -0.1～-0.15 -0.18～-0.19 -0.18
Temperature Coefficent iHc %/K ― ― 0.35～0.5 0.35
Curie Point
Tc		 K ※393 ※393 ※353 ※353
℃ ※120 ※120 ※80 ※80
Recoil Relative Magnetic
Permeability
μrec		 ― 1.1～1.2 1.1～1.2 1.03～1.07 1.03～1.07
Density ｇ/cm3 5.6～6.2 4.2～5.5 3.7 3.7
Deflecting Strength Mpa 49.0～58.8 ― ― ―
Kgf/mm3 5.0～6.0
Compression Strength MPa ― ― ― ―
Kgf/mm3
Tensile Strength MPa ― 30000 666 392
Kgf/mm3 3061 68 40
Specific Heat J/(Kg・K） ― ― 0.7～0.8×103 0.7～0.8×103
cal/g・℃ 0.167～0.191 0.167～0.191
Vickers Hardness HV 430 430 760 450
Thermal Expansion Coefficient
Lateral		 ppm/K 13～15 50 ― ―
Thermal Expansion Coefficient
Vertical		 ppm/K 13～15 50 100～150 100～150
JIS ― REFe63/64p REFe63/64p ― ―
MMPA ― ― ― ― ―
Magnetic Field To Be Charged
For Magnetization		 kA/m 2000 2000 800 800
KOe 25 25 10 10
Electric Resistance nΩ・m 56×103 56×103 ― ―