Sintered neodymium magnets are the most powerful commercially available magnets in the world . They are made from an alloy of neodymium, iron, and boron, and are produced using a powder metallurgy process .

Sintered neodymium magnets have the highest energy product among all types of permanent magnets. They are known for their high magnetic strength, excellent temperature stability, and good corrosion resistance .

Here are some of the Physical Properties of sintered neodymium magnets:

Br Temperature Coefficient-0.095~-0.105%/°CDensity7.3-7.5g/cm3Curie Temperature310-340°C
Coercivity Temperature Coefficient-0.45~-0.60%/°CVickers-hardness600HVElectrical Resistivity114μΩ·cm
 Across Transfiguration Coefficient0.24Break Strength8.0Kgf/mm2Bending Strength25kgf/mm2
Thermal Expansion Coefficient4×10-6/°CSpecific Heat0.12Kcal/KgStiffness0.64N/m2
The Conduction Coefficient7.7kcal/[m.h. °C]Young’s Modulus1.6×1011N/m2Compressibility9.8×10-12m2/N

Surface Treatment

CoatingThickness(μm)ColorSST(hrs)PCT/HAST(hrs)Operation Temperature (°C)Corrosive ResistanceApplication
Zn4-15Bright blue24≤160GoodSuitable for working conditions with low corrosive and humidity requirements.
Ni-Cu-Ni5-20Bright silver4848≤200ExcellentMost regular used multi-layer coating.
Electroless Ni5-20Dark silver7248≤200Excellent performance with uniform appearance.Suitable for working conditions with high corrosive and humidity requirements.
Ni-Cu-Ni-Au5-20Golden7296≤200GoodSuitable for parts that placed into the high reliable electronic equipments or decoration.
Ni-Cu-Ni-Ag5-20Silver7296≤160GoodSuitable for parts that may be welded or placed into the electric equipment.
Ni-Cu-Ni-Sn5-20Silver7296≤200ExcellentSuitable for parts that may be welded or placed into electric equipment.
Passivation1-3Dark grey≤200PoorTemporary protection.
Aluminum2-15Bright silver240168≤400ExcellentSuitable for working conditions with very high corrosive and humidity requirements.
Epoxy resin10-30Black/Grey9624≤160Excellent. Superior binding force.Suitable for parts used to insulate the electric equipments or placed in the high corrosive industrial atmosphere.
Parylene5-20Colorless168≤200ExcellentFree of pore. Suitable for biomedical applications.
Everlube10-15Golden yellow9672≤200ExcellentSuitable for working conditions with very high corrosive and humidity requirements.
Note:1. The SST results differ from coating. In general, Salt Spray Test results, which is coated by grinding (small size magnets), is better than the one, which is coated by hanging up (big size magnets).2. Salt Spray Test (SST) condition: 5% NaCl, 35℃, continuously spray a certain time, test whether there is corrosion on coating surface.3. Pressure Cooking Test (PCT) condition: 2 atm, 95% RH (relative humidity), 121℃ to test the coating adhesion. (Zinc, Passivated, and Epoxy are not suitable for PCT).4. Other test methods for coating: Drop Test, Cross Cut test, Heating and Spilling Test, Constant Temperature and Humidity Test and etc.

Magnetic Properties

SeriesGradeBrHcbHcj(BH)maxTW
mTKGsKA/mkOekA/mkOekJ/m3MGOe°C
NN351170-122011.7-12.2≥868≥10.9≥955≥12263-28733-36≤80
N381220-125012.2-12.5≥899≥11.3≥955≥12287-31036-39≤80
N401250-128012.5-12.8≥907≥11.4≥955≥12302-32638-41≤80
N421280-132012.8-13.2≥915≥11.5≥955≥12318-34240-43≤80
N451320-138013.2-13.8≥923≥11.6≥955≥12342-36643-46≤80
N481380-142013.8-14.2≥923≥11.6≥955≥12366-39046-49≤80
N501400-145014.0-14.5≥860≥10.8≥955≥12382-40648-51≤80
N521430-148014.3-14.8≥860≥10.8≥955≥12398-42250-53≤80
N541460-150014.6-15.0≥860≥10.8≥955≥12414-43853-57≤80
N561480-152014.8-15.2≥836≥10.5≥875≥11422-45453-57≤80
M35M1170-122011.7-12.2≥868≥10.9≥1114≥14263-28733-36≤100
38M1220-125012.2-12.5≥899≥11.3≥1114≥14287-31036-39≤100
40M1250-128012.5-12.8≥923≥11.6≥1114≥14302-32638-41≤100
42M1280-132012.8-13.2≥955≥12.0≥1114≥14318-34240-43≤100
45M1320-138013.2-13.8≥995≥12.5≥1114≥14342-36643-46≤100
48M1360-143013.6-14.3≥1027≥12.9≥1114≥14366-39046-49≤100
50M1400-145014.0-14.5≥1033≥13.0≥1114≥14382-40648-51≤100
52M1420-148014.2-14.8≥1043≥13.1≥1114≥14398-42250-53≤100
54M1450-150014.5-15.0≥995≥12.5≥1035≥13406-43851-55≤100
H35H1170-122011.7-12.2≥868≥10.9≥1353≥17263-28733-36≤120
38H1220-125012.2-12.5≥899≥11.3≥1353≥17287-31036-39≤120
40H1250-128012.5-12.8≥923≥11.6≥1353≥17302-32638-41≤120
42H1280-132012.8-13.2≥955≥12.0≥1353≥17318-34240-43≤120
45H1300-136013.0-13.6≥963≥12.1≥1353≥17326-35843-46≤120
48H1370-143013.7-14.3≥995≥12.5≥1353≥17366-39046-49≤120
50H1400-145014.0-14.5≥1003≥12.6≥1353≥17382-40648-51≤120
52H1420-148014.2-14.8≥1035≥13.0≥1353≥17390-42249-53≤120
SH33SH1130-117011.3-11.7≥860≥10.6≥1592≥20247-27131-34≤150
35SH1170-122011.7-12.2≥876≥11.0≥1592≥20263-28733-36≤150
38SH1220-125012.2-12.5≥907≥11.4≥1592≥20287-31036-39≤150
40SH1240-128012.5-12.8≥939≥11.8≥1592≥20302-32638-41≤150
42SH1280-132012.8-13.2≥963≥12.1≥1592≥20318-34240-43≤150
45SH1320-138013.2-13.8≥979≥12.3≥1592≥20342-36643-46≤150
48SH1370-143013.7-14.3≥1019≥12.8≥1592≥20366-39046-49≤150
50SH1400-145014.0-14.5 ≥1019≥12.8≥1592≥20374-40647-51≤150
52SH1420-148014.2-14.8≥1035≥13.0≥1512≥19390-42249-53≤150
UH28UH1020-108010.2-10.8≥764≥9.6≥1990≥25207-23126-29≤180
30UH1080-113010.8-11.3≥812≥10.2≥1990≥25223-24728-31≤180
33UH1130-117011.3-11.7≥852≥10.7≥1990≥25247-27131-34≤180
35UH1180-122011.8-12.2≥860≥10.8≥1990≥25263-28733-36≤180
38UH1220-125012.2-12.5≥899≥11.0≥1990≥25287-31036-39≤180
40UH1250-128012.5-12.8≥939≥11.3≥1990≥25302-32638-41≤180
42UH1280-132012.8-13.2≥963≥12.1≥1990≥25318-34240-43≤180
45UH 1320-1380 13.2-13.8 ≥979≥12.3≥1990≥25342-36643-46≤180
48UH 1380-1420 13.8-14.2 ≥1019≥12.8≥1910≥24366-39046-49≤180
EH28EH1040-109010.4-10.9≥780≥9.8≥2388≥30207-23126-29≤200
30EH1080-113010.8-11.3≥812≥10.2≥2388≥30223-24728-31≤200
33EH1130-117011.3-11.7≥836≥10.5≥2388≥30247-27131-34≤200
35EH1170-122011.7-12.2≥876≥11.0≥2388≥30263-28733-36≤200
38EH1220-125012.2-12.5≥899≥11.3≥2388≥30287-31036-39≤200
40EH1250-128012.5-12.8≥923≥11.6≥2388≥30302-32638-41≤200
42EH1280-132012.8-13.2≥931≥11.7≥2388≥30318-34240-43≤200
45EH1330-138013.3-13.8≥995≥12.5≥2308≥29342-36643-46≤200
AH28AH1040-109010.4-10.9≥787≥9.9≥2624≥33207-23126-29≤230
30AH1080-113010.8-11.3≥819≥10.3≥2624≥33223-24728-31≤230
33AH1130-117011.3-11.7≥843≥10.6≥2624≥33247-27131-34≤230
35AH1170-122011.7-12.2≥876≥11.0≥2624≥33263-28733-36≤230
38AH1220-125012.2-12.5≥899≥11.3≥2624≥33287-31036-39≤230
40AH 1250-1280 12.5-12.8 ≥923≥11.6≥2624≥33302-32638-41≤230
42AH 1290-1330 12.9-13.3 ≥955≥12.0≥2624≥33318-34240-43≤230

Temperature Characteristics

Low grade Neodymium magnet may lose strength if heated above 80°C. High grade Neo magnets have been developed to function at temperatures up to 220°C with little irreversible loss. The need for low temperature coefficient in neodymium magnet applications has triggered several grades to be developed to meet specific operating requirements. 

Application

The utility of Sintered NdFeB magnet extends across a wide spectrum of industries, including to electronics (such as mobile phones and hard drives), automotive engineering (in motors and sensors), medical technology (in MRI machines), and the energy transportation sector. As technology development, Sintered NdFeB magnet is poised for significant growth in emerging areas such as electric vehicles, wind power generation, and energy-efficient household appliances. This material has redefined the boundaries of what is achievable in the field of magnetic materials, making it a cornerstone of modern engineering.

By Peacean

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