D4.4×1.0 Computer Sintered NdFeB Magnets

Sintered NdFeB Magnets

Sintered NdFeB magnets are the most powerful magnets known. The maximum allowable temperature varies, but some grades are up to 240°C. This maximum temperature is important because the price of magnets increases with temperature.

Magnets consist of powder compacted in a magnetic field, so they have process fixed and limited magnetization directions. Usually the magnetic field lines must be parallel.

However, due to the low corrosion resistance of the material, corrosion protection of sintered neodymium magnets is always recommended. Corrosion resistance comparable to untreated pure iron. There are a range of different coatings(Nickel,Zinc,Epoxy, Parylene, Everlube,etc.) to choose from, but sometimes it is best to be completely encapsulated in stainless steel.

Magnetic Process

Magnetic Parameters

			QINGDAO MAGNET MAGNETIC MATERIAL CO.,LTD. Sintered NdFeB Magnet Performance Parameter
Grade	Br(20℃)		Coercivity				BH(max)(20℃)		Temperature Coefficient			Density	Max.Working Temp.
	Br		Hcj		Hcb		BH(max) MGOe		T1-T2	TK(Br) Reference	TK(Hcj) Reference	ρ Reference	Tmax Reference
	T	KGs	kA/m	kOe	kA/m	kOe	kJ/m³	MGOe	℃	％/℃	％/℃	g/cm³	℃	℉
N35	1.18-1.24	11.8-12.4	≥955	≥12	≥860	≥10.8	263-295	33-37	20-80	-0.105	-0.75	7.45	80	176
N38	1.23-1.28	12.3-12.8	≥955	≥12	≥899	≥11.3	287-310	36-39				7.45	80	176
N40	1.26-1.31	12.6-13.1	≥955	≥12	≥915	≥11.5	302-326	38-41				7.45	80	176
N42	1.29-1.34	12.9-13.4	≥955	≥12	≥915	≥11.5	318-350	40-44				7.50	80	176
N45	1.33-1.38	13.3-13.8	≥955	≥12	≥915	≥11.5	342-366	43-46				7.50	80	176
N48	1.37-1.41	13.7-14.1	≥955	≥12	≥915	≥11.5	358-382	45-48				7.55	80	176
N50	1.39-1.43	13.9-14.3	≥955	≥12	≥915	≥11.5	374-398	47-50				7.55	80	176
N52	1.42-1.47	14.2-14.7	≥955	≥12	≥915	≥11.5	390-414	49-52				7.60	80	176
N54	1.45-1.50	14.5-14.0	≥876	≥11	≥836	≥10.5	406-430	51-54				7.60	80	176
35M	1.18-1.24	11.8-12.4	≥1114	≥14	≥868	≥10.9	263-295	33-37	20-100	-0.105	-0.70	7.45	100	212
38M	1.23-1.28	12.3-12.8	≥1114	≥14	≥907	≥11.4	287-310	36-39				7.45	100	212
40M	1.26-1.31	12.6-13.1	≥1114	≥14	≥931	≥11.7	302-326	38-41				7.50	100	212
42M	1.29-1.34	12.9-13.4	≥1114	≥14	≥955	≥12.0	318-350	40-44				7.50	100	212
45M	1.33-1.38	13.3-13.8	≥1114	≥14	≥987	≥12.4	342-366	43-46				7.55	100	212
48M	1.37-1.41	13.7-14.1	≥1114	≥14	≥1019	≥12.8	358-382	45-48				7.55	100	212
50M	1.39-1.43	13.9-14.3	≥1114	≥14	≥1035	≥13.0	374-398	47-50				7.60	100	212
52M	1.42-1.47	14.2-14.7	≥1114	≥14	≥1059	≥13.3	390-414	49-52				7.60	100	212
54M*	1.45-1.50	14.5-14.0	≥1114	≥14	≥1075	≥13.5	406-430	51-54				7.60	100	212
35H	1.18-1.24	11.8-12.4	≥1353	≥17	≥876	≥11.0	263-295	33-37	20-120	-0.105	-0.60	7.45	120	248
38H	1.23-1.28	12.3-12.8	≥1353	≥17	≥915	≥11.5	287-310	36-39				7.45	120	248
40H	1.26-1.31	12.6-13.1	≥1353	≥17	≥939	≥11.8	302-326	38-41				7.50	120	248
42H	1.29-1.34	12.9-13.4	≥1353	≥17	≥963	≥12.1	318-350	40-44				7.50	120	248
45H	1.33-1.38	13.3-13.8	≥1353	≥17	≥995	≥12.5	342-366	43-46				7.55	120	248
48H	1.37-1.41	13.7-14.1	≥1274	≥16	≥1027	≥12.9	358-382	45-48				7.55	120	248
50H	1.39-1.43	13.9-14.3	≥1274	≥16	≥1043	≥13.1	374-398	47-50				7.60	120	248
52H*	1.42-1.47	14.2-14.7	≥1274	≥16	≥1067	≥13.4	390-414	49-52				7.60	120	248
35SH	1.18-1.24	11.8-12.4	≥1592	≥20	≥884	≥11.1	263-295	33-37	20-150	-0.105	-0.55	7.50	150	302
38SH	1.23-1.28	12.3-12.8	≥1592	≥20	≥923	≥11.6	287-310	36-39				7.50	150	302
40SH	1.26-1.31	12.6-13.1	≥1592	≥20	≥947	≥11.9	302-326	38-41				7.55	150	302
42SH	1.29-1.34	12.9-13.4	≥1592	≥20	≥971	≥12.0	318-350	40-44				7.55	150	302
45SH	1.33-1.38	13.3-13.8	≥1592	≥20	≥1003	≥12.6	342-366	43-46				7.60	150	302
48SH	1.37-1.41	13.7-14.1	≥1592	≥20	≥1035	≥13.0	358-382	45-48				7.60	150	302
50SH	1.39-1.43	13.9-14.3	≥1592	≥20	≥1051	≥13.2	374-398	47-50				7.60	150	302
52SH*	1.42-1.47	14.2-14.7	≥1592	≥20	≥1075	≥13.3	390-414	49-52				7.60	150	302
30UH	1.08-1.15	10.8-11.5	≥1990	≥25	≥812	≥10.2	223-255	28-32	20-180	-0.115	-0.45	7.55	180	356
33UH	1.14-1.19	11.4-11.9	≥1990	≥25	≥860	≥10.8	247-271	31-34				7.55	180	356
35UH	1.18-1.24	11.8-12.4	≥1990	≥25	≥892	≥11.2	263-295	33-37				7.55	180	356
38UH	1.23-1.28	12.3-12.8	≥1990	≥25	≥931	≥11.7	287-310	36-39				7.60	180	356
40UH	1.26-1.31	12.6-13.1	≥1990	≥25	≥955	≥12.0	302-326	38-41				7.60	180	356
42UH	1.29-1.34	12.9-13.4	≥1990	≥25	≥979	≥12.3	318-350	40-44				7.60	180	356
45UH	1.33-1.38	13.3-13.8	≥1990	≥25	≥1011	≥12.7	342-366	43-46				7.60	180	356
48UH*	1.36-1.40	13.6-14.0	≥1990	≥25	≥1035	≥13.0	358-382	45-48				7.60	180	356
50UH*	1.38-1.42	13.8-14.2	≥1990	≥25	≥1051	≥13.2	374-398	47-50				7.60	180	356
30EH	1.08-1.15	10.8-11.5	≥2388	≥30	≥820	≥10.3	223-255	28-32	20-200	-0.115	-0.45	7.55	200	392
33EH	1.14-1.19	11.4-11.9	≥2388	≥30	≥868	≥10.9	247-271	31-34				7.55	200	392
35EH	1.18-1.24	11.8-12.4	≥2388	≥30	≥899	≥11.3	263-295	33-37				7.6	200	392
38EH	1.22-1.26	12.2-12.6	≥2388	≥30	≥931	≥11.7	287-310	36-39				7.6	200	392
40EH	1.25-1.29	12.6-13.1	≥2388	≥30	≥955	≥12.0	302-326	38-41				7.65	200	392
42EH*	1.28-1.32	12.8-13.2	≥2388	≥30	≥979	≥12.3	318-350	40-44				7.65	200	392
45EH*	1.32-1.37	13.2-13.7	≥2388	≥30	≥1011	≥12.7	342-366	43-46				7.65	200	392
48EH*	1.36-1.40	13.6-14.0	≥2388	≥30	≥1035	≥13.0	358-382	45-48				7.65	200	392
30TH	1.08-1.15	10.8-11.5	≥2786	≥35	≥820	≥10.3	223-255	28-32	20-250	-0.115	-0.40	7.6	250	482
33TH	1.14-1.19	11.4-11.9	≥2786	≥35	≥868	≥10.9	247-271	31-34				7.6	250	482
35EH	1.18-1.24	11.8-12.4	≥2786	≥35	≥899	≥11.3	263-295	33-37				7.65	250	482
38EH	1.22-1.26	12.2-12.6	≥2786	≥35	≥931	≥11.7	287-310	36-39				7.65	250	482
40EH*	1.25-1.29	12.6-13.1	≥2786	≥35	≥955	≥12.0	302-326	38-41				7.65	250	482
Note: Grades with *marked apply special processes.

The advantages of sintered neodymium magnets are:

The highest magnet strength available
High resistance to demagnetization
Operating temperature up to 240°C
Good at low temperature resistance. (down to – 100°C)
Possibility of more coils
Reduce waste - especially with complex geometries

Maximum operating temperature

Although the Curie temperature of NdFeB materials is around 310 ºC for 0% cobalt and higher than 370 ºC for 5% cobalt, some irreversible output loss may occur even at moderate temperatures. The new magnets also have a moderately high reversible temperature coefficient of induction, with the total magnetic output decreasing with increasing temperature. The choice of neodymium magnets over SmCo is a function of the maximum temperature of the application, the desired magnetic output at typical operating temperatures, and the total system cost.

The new magnet also has some limitations due to its corrosive behavior. In wet environments, a protective coating or electroplating is strongly recommended. Coatings that have been successfully applied include: electronic coatings, powder coatings, nickel plating, zinc plating, parylene, and combinations of these coatings.