Ferrite Magnets 1
Ferrite Magnet

The hard ferrite is manufactured with SrO or BaO and Fe2O3 by ceramic process,it is also called ceramic mangets. Because of its cheaper price, and production process is relatively simple, compared with the prices of their products relatively cheap in terms of other magnets. The main raw materials of ferrite magnets is oxide, so, it could not be eroded due to the impact of chemical substances or the environment (except for acid). Therefore, the surface does not need electroplating treatment. It is mainly used in handicrafts, drawing annex, toys, motor, loud speakers.

Sintered Ferrite Magnets

Hard ferrite magnets are manufactured by a die pressing followed by sintering process which allows economic production of components in a varied array of sizes and shapes. Ferrite magnets have excellent corrosion resistance and have normal operating capabilities between -40 oC and +250 oC.

Applications of Ceramic Magnet
·Speaker magnets
·DC brushless motors
·Magnetic Resonance Imaging (MRI)
·DC permanent magnet motors (used in cars)
·Separators (separate ferrous material from
·Used in magnetic assemblies designed for lifting,
Holding,retrieving and separating
·Magnetic Door Catcher
·Instrument and Meters
·Toys
·Arts and crafts
Attributes of Ceramic Magnet
·High intrinsic coercive force
·Available in simple shapes only due to manufacturing process
·Lower service temperature than alnico, greater than rare earth
·Lower energy product than alnico and rare earth magnets
Attributes of Ceramic Magnet
·High intrinsic coercive force
·Available in simple shapes only due to manufacturing process
·Lower service temperature than alnico, greater than rare earth
·Lower energy product than alnico and rare earth magnets

Magnetic Properties of Sintered Ferrite Magnets

National standard

Grade Value
Br Hcb(BHC) Hcj(IHC) (BH)max
mT KG KA/m KOe KA/m KOe Kj/m3 MGOe
Y10T(=C1) 200/218 2.00/2.18 125/145 1.57/1.82 210/250 2.64/3.14 6.5/8.0 0.8/1.0
Y25 360/370 3.60/3.70 135/150 1.70/1.88 140/170 1.76/2.14 22.5/25.3 2.8/3.2
Y30(=C5) 380/385 3.80/3.85 191/210 2.40/2.64 199/220 2.50/2.51 26.0/28 3.4/3.7
Y30BH 380/390 3.80/3.90 223/235 2.80/2.95 231/245 2.90/3.08 27.0/30.0 3.4/3.7
Y33 410/420 4.10/4.20 220/235 2.77/2.95 225/240 2.83/3.01 31.5/33.0 4.0/4.2
Y35 400/410 4.00/4.10 175/195 2.20/2.45 180/200 2.26/2.51 30.0/32.0 3.8/4.0
C8(=C8A) 385/390 3.85/3.90 235/255 2.95/3.20 242/265 3.05/3.33 27.8/30.0 3.5/3.7
C10 400/410 4.00/4.10 288/300 3.62/3.77 280/287 3.51/3.60 30.4/31.9 3.8/4.0

Chinese standard

Material Br HcB HcJ (BH)max
mT KG KA/m Oe KA/m Oe Kj/m3 MGOe
Y8T 200~235 ≥2000 125~160 ≥1570 210~280 ≥2610 6.5~9.5 ≥0.8
Y22H 310~360 ≥3100 220~250 ≥2770 280~320 ≥3520 20.0~24.0 ≥2.5
Y25 360~400 ≥3600 135~170 ≥1700 140~200 ≥1760 22.5~28.0 ≥2.8
Y26H-1 360~390 ≥3600 220~250 ≥2512 225~255 ≥2830 23.0~28.0 ≥2.9
Y26H-2 360-380 ≥3600 263-288 ≥3300 318-350 ≥4000 24.0-28.0 ≥3.0
Y27H 370~400 ≥3500 225-240 ≥2830 235-260 ≥2950 25.0~29.0 ≥3.1
Y28 370-400 ≥3700 175-210 ≥2200 180-220 ≥2260 26.0-30.0 ≥3.3
Y28H-1 380-400 ≥3800 240-260 ≥3020 250-280 ≥3140 27.0-30.0 ≥3.1
Y28H-2 360-380 ≥3600 271-295 ≥3400 382-405 ≥1800 26.0-30.0 ≥3.3
Y30 370~400 3.7~4.0 175~210 2.20~2.64 180~220 2.26~2.77 26.0~30.0 3.3~3.8
Y30H-1 380~400 ≥3800 230-275 ≥2890 235-290 ≥2950 27.0~32.5 ≥3.4
Y30H-2 395-415 ≥3950 275-300 ≥3460 310-335 ≥3900 27.0~32.0 ≥3.4
Y32 400~420 ≥4000 160~190 ≥2010 165~195 ≥2070 30.0~33.5 ≥3.8
Y32H-1 400-420 ≥4000 190-230 ≥2390 230-250 ≥2890 34.5-35.0 ≥4.0
Y32H-2 400-440 ≥4000 224-240 ≥2810 230-250 ≥2890 31.0-34.0 ≥3.9
Y33 410~430 ≥4100 220~250 ≥2760 225~255 ≥2830 31.5~35.0 ≥4.0
Y33H 410-430 ≥4100 250-270 ≥3140 250-275 ≥3140 31.5-35.0 ≥4.0
Y34 420-440 ≥4200 200-230 ≥2510 205-235 ≥2580 32.5-36.0 ≥4.1
Y35 430-450 ≥4300 215-239 ≥2700 217-242 ≥2730 33.1-33.2 ≥4.2
Y36 440-450 ≥4400 247-271 ≥3100 250-374 ≥4400 35.1-38.3 ≥4.4
Y38 440-460 ≥4400 285-305 ≥3580 294-310 ≥3690 36.6-40.6 ≥4.6
Y40 450-460 ≥4500 330-354 ≥4150 340-360 ≥4270 37.6-41.8 ≥4.7

USA standard

Material Br HcB HcJ (BH)max
mT KG KA/m KOe KA/e KOe kj/m3 MGOe
C1 230 2.3 148 1.86 258 3.5 8.36 1.05
C5 380 3.8 191 2.4 199 2.5 27 3.4
C7 340 3.4 258 3.23 318 4.00 21.9 2.75
C8(=C8A) 385 3.85 235 2.95 242 3.05 27.8 3.5
C8B 420 4.2 232 2.913 236 2.96 32.8 4.12
C9 380 3.8 280 3.516 320 4.01 26.4 3.32
C10 400 4.0 288 3.617 280 3.51 30.4 3.82
C11 430 4.3 200 2.512 204 2.56 34.4 4.32

Europe standard

The standard from International Electronics Committee(IEC404-8-1)

Grade Allowed Value (min/typical)
Br Hcb(BHC) Hcj(IHC) (BH)max
MT KG KA/m KOe KA/m KOe Kj/m3 MGOe
HF8/22 200/220 2.00/2.20 125/140 1.57/1.76 220/230 2.76/2.89 6.5/6.8 0.8/1.1
HF20/19 320/333 3.20/3.33 170/190 2.14/2.39 190/200 2.39/2.51 20.0/21.0 2.5/2.7
HF20/28 310/325 3.10/3.25 220/230 2.76/2.89 280/290 3.52/3.64 20.0/21.0 2.5/2.7
HF22/30 350/365 3.50/3.65 255/265 3.20/3.33 290/300 3.64/3.77 22.0/23.5 2.8/3.0
HF24/16 350/365 3.50/3.65 155/175 1.95/2.20 160/180 2.01/2.26 24.0/25.5 3.0/3.2
HF24/23 350/365 3.50/3.65 220/230 2.76/2.89 230/240 2.89/3.01 24.0/25.5 3.0/3.2
HF24/35 360/370 3.60/3.70 260/270 3.27/3.39 350/360 4.40/4.52 24.0/25.5 3.0/3.2
HF26/16 370/380 3.70/3.80 155/175 1.95/2.20 160/180 2.01/2.26 26.0/27.0 3.2/3.4
HF26/18 370/380 3.70/3.80 175/190 2.20/2.39 180/190 2.26/2.39 26.0/27.0 3.3/3.4
HF26/24 370/380 3.70/3.80 230/240 2.89/3.01 240/250 3.01/3.14 26.0/27.0 3.3/3.4
HF26/26 370/380 3.70/3.80 230/240 2.89/3.01 260/270 3.27/3.39 26.0/27.0 3.3/3.4
HF26/30 385/395 3.85/3.95 260/270 3.27/3.39 300/310 3.77/3.89 26.0/27.0 3.3/3.4
HF28/26 385/395 3.85/3.95 250/265 3.14/3.33 260/275 3.27/3.45 28.0/30.0 3.5/3.8
HF28/28 385/395 3.85/3.95 260/270 3.27/3.39 280/290 3.50/3.60 28.0/30.0 3.5/3.8
HF30/26 395/405 3.95/4.05 250/260 3.14/3.33 260/270 3.27/3.39 30.0/31.5 3.8/3.9
HF32/17 410/420 4.10/4.20 160/180 2.01/2.26 165/175 2.07/2.20 32.0/33.0 4.0/4.1
HF32/22 410/420 4.10/4.20 215/225 2.70/2.83 220/230 2.76/2.89 32.0/33.0 4.0/4.1
HF32/25 410/420 4.10/4.20 240/250 3.01/3.14 250/260 3.14/3.27 32.0/33.0 4.0/4.1

Japan TDK standard

Grade Composition Br Hcb Hcj BH max
mT kG kA/m kOe kA/m kOe KJ/m3 MGOe
FB40 SrO6Fe2O3 410+/-10 4.1+/-10 234.8+/-11.9 2.95+/-0.15 238.7+/-15.9 3.0+/-0.2 31.4+/-1.6 3.95+/-0.2
FB3N SrO6Fe2O3 395+/-15 3.95+/-15 234.8+/-11.9 2.95+/-0.15 238.7+/-15.9 3.0+/-0.2 28.7+/-2.4 3.6+/-0.3
FB3G SrO6Fe2O3 375+/-15 3.75+/-15 254.6+/-15.9 3.2+/-0.2 270.6+/-19.9 3.4+/-0.25 25.9+/-2.4 3.25+/-0.3
FB3X SrO6Fe2O3 375+/-15 3.75+/-15 234.8+/-11.9 2.95+/-0.15 238.7+/-15.9 3.0+/-0.2 25.9+/-2.4 3.25+/-0.3
FB1A SrO6Fe2O3 220+/-15 2.20+/-15 159.2+/-15.9 2.0+/-0.2 258.6+/-19.9 3.25+/-0.25 8.9+/-1.6 1.1+/-0.2
FB5H SrO6Fe2O3 405+/-15 4.05+/-15 298.4+/-11.9 3.75+/-0.15 322.3+/-11.9 4.05+/-0.15 31.1+/-1.6 3.9+/-0.2
FB4X SrO6Fe2O3 420+/-10 4.20+/-10 234.8+/-11.9 2.95+/-0.15 238.7+/-15.9 3.0+/-0.2 33.4+/-1.6 4.2+/-0.2
FB4B SrO6Fe2O3 400+/-10 4.00+/-10 254.6+/-11.9 3.2+/-0.2 262.6+/-19.9 3.3+/-0.25 30.3+/-1.6 3.8+/-0.2
FB4A SrO/
BaO6Fe2O3		 410+/-10 4.10+/-10 175.1+/-15.9 2.2+/-0.2 176.7+/-15.9 2.22+/-0.2 31.8+/-1.6 4.0+/-0.2
FBGN SrO6Fe2O3 440+/-10 4.40+/-10 258.6+/-11.9 3.25+/-0.15 262.6+/-11.9 3.3+/-0.15 36.7+/-1.6 4.6+/-0.2
FB6B SrO6Fe2O3 420+/-10 4.20+/-10 302.4+/-11.9 3.8+/-0.15 318.3+/-11.9 4.0+/-0.15 33.4+/-1.6 4.2+/-0.2
FB6H SrO6Fe2O3 400+/-10 4.00+/-10 302.4+/-11.9 3.8+/-0.15 358.1+/-11.9 4.5+/-0.15 30.3+/-1.6 3.8+/-0.2
FB6E SrO6Fe2O3 380+/-10 3.80+/-10 290.5+/-11.9 3.65+/-0.15 393.9+/-11.9 4.95+/-0.15 27.5+/-1.6 3.45+/-0.2
FB5N SrO6Fe2O3 440+/-10 4.40+/-10 256.8+/-11.9 2.85+/-0.15 2259.2+/-11.9 2.88+/-0.15 36.7+/-1.6 4.6+/-0.2
FB5B SrO6Fe2O3 420+/-10 4.20+/-10 262.6+/-11.9 3.3+/-0.15 266.6+/-11.9 3.35+/-0.15 33.4+/-1.6 4.2+/-0.2

Physical Characteristics

Compressive Strength 1.4 x 104 kg/cm2
Required Magnetizing Field 12,000 – 15,000 Oe
Electrical Resistivity > 104 μ-ohm-cm/cm2
Density 4.7-5.0 g/cm3
Recoil Permeability 1.05 μr
Rev. Temp. Coeff. -0.20 %/°C