Understanding Neodymium Magnets: Grades, Properties, and Working Temperatures

Neodymium magnets, also known as NdFeB magnets or rare earth magnets, are the strongest permanent magnets commercially available today. Since their development in the 1980s, these powerful magnets have revolutionized industries — from electronics to automotive to green energy.

In this post, we’ll break down the essentials of neodymium magnets, including magnet grades, magnetic properties, temperature ratings, and how to choose the right magnet for your application.

What Is a Neodymium Magnet?

Neodymium magnets are made from an alloy of neodymium (Nd), iron (Fe), and boron (B), commonly written as Nd₂Fe₁₄B. These magnets are sintered or bonded into different shapes and sizes, offering extremely high magnetic strength relative to their volume and mass.

Neodymium Magnet Grades: What Do They Mean?

Grades of neodymium magnets are typically expressed with a letter “N” followed by a number (e.g., N35, N52). This number refers to the maximum energy product of the magnet, measured in Mega Gauss Oersteds (MGOe), indicating how much magnetic energy the magnet can store.

Common Grades Include:

Grade	Maximum Energy Product (MGOe)	General Use
N35	33–35	Cost-effective, standard applications
N42	40–42	Balanced performance and price
N52	50–53	Highest magnetic strength, premium price

Higher numbers = stronger magnetic field, but possibly lower heat resistance.

Magnetic Properties of Neodymium Magnets

Here are key magnetic characteristics:

Property	Symbol	Unit	Description
Remanence	Br	Tesla (T) or Gauss (G)	Magnet strength at surface
Coercivity	Hc	kOe or kA/m	Resistance to demagnetization
Maximum Energy Product	(BH)max	MGOe	Total energy stored
Curie Temperature	Tc	°C	Point at which magnetism is lost

For example, an N52 magnet may have a remanence (Br) of up to 1.45 T, which is extremely powerful for a small magnet.

Working Temperature: Heat Resistance of NdFeB Magnets

Neodymium magnets are sensitive to heat. Exceeding their maximum operating temperature can result in permanent loss of magnetism.

Grade	Max Operating Temp	Remarks
N35–N52	80°C (176°F)	Standard
N35M–N52M	100°C (212°F)	Medium temperature
N35H–N52H	120°C (248°F)	High-temperature grade
N35SH–N52SH	150°C (302°F)	Super high
N35UH–N50UH	180°C (356°F)	Ultra high
N35EH–N48EH	200°C (392°F)	Extra high
N35AH–N45AH	230°C (446°F)	Advanced high temp

Note: Higher temperature grades have slightly lower magnetic strength due to changes in composition.

Magnetics Properties Sintered NdFeB Magnets

GRADE	remanence		Coercive force		intrinsic coercive force		Maximum energy product		HIGHEST WORKING TEMPERATURE	DENSITY
	Br		Hcb		Hcj		(BH)max
	T	kGs	kA/m	kOe	kA/m	kOe	kJ/m3	MGOe	℃	g/cm3
N30	1.08-1.13	10.8-11.3	≥798	≥10.0	≥955	≥12	223-247	28-31	80	≥7.5
N33	1.13-1.17	11.3-11.7	≥836	≥10.5	≥955	≥12	247-271	31-34	80	≥7.5
N35	1.17-1.22	11.7-12.2	≥868	≥10.9	≥955	≥12	263-287	33-36	80	≥7.5
N38	1.22-1.25	12.2-12.5	≥899	≥11.3	≥955	≥12	287-310	36-39	80	≥7.5
N40	1.25-1.28	12.5-12.8	≥907	≥11.4	≥955	≥12	302-326	38-41	80	≥7.5
N42	1.28-1.32	12.8-13.2	≥915	≥11.5	≥955	≥12	318-342	40-43	80	≥7.5
N45	1.32-1.38	13.2-13.8	≥923	≥11.6	≥955	≥12	342-366	43-46	80	≥7.5
N48	1.38-1.42	13.8-14.2	≥923	≥11.6	≥955	≥12	366-390	46-49	80	≥7.5
N50	1.40-1.45	14.0-14.5	≥796	≥10.0	≥876	≥11	382-406	48-51	80	≥7.5
N52	1.43-1.48	14.3-14.8	≥796	≥10.0	≥876	≥11	398-422	50-53	80	≥7.5
N55	1.46-1.52	14.6-15.2	≥796	≥10.0	≥876	≥11	414-430	52-54	80	≥7.5
N35M	1.17-1.22	11.7-12.2	≥868	≥10.9	≥1114	≥14	263-287	33-36	100	≥7.5
N38M	1.22-1.25	12.2-12.5	≥899	≥11.3	≥1114	≥14	287-310	36-39	100	≥7.5
N40M	1.25-1.28	12.5-12.8	≥923	≥11.6	≥1114	≥14	302-326	38-41	100	≥7.5
N42M	1.28-1.32	12.8-13.2	≥955	≥12.0	≥1114	≥14	318-342	40-43	100	≥7.5
N45M	1.32-1.38	13.2-13.8	≥995	≥12.5	≥1114	≥14	342-366	43-46	100	≥7.5
N48M	1.37-1.43	13.7-14.3	≥1027	≥12.9	≥1114	≥14	366-390	46-49	100	≥7.5
N50M	1.40-1.45	14.0-14.5	≥1033	≥13.0	≥1114	≥14	382-406	48-51	100	≥7.5
N52M	1.43-1.48	14.3-14.8	≥1050	≥13.2	≥1114	≥14	398-422	50-53	100	≥7.5
N54M	1.45-1.50	14.5-15.0	≥1051	≥13.2	≥1114	≥14	414-438	52-55	100	≥7.5
N35H	1.17-1.22	11.7-12.2	≥868	≥10.9	≥1353	≥17	263-287	33-36	120	≥7.5
N38H	1.22-1.25	12.2-12.5	≥899	≥11.3	≥1353	≥17	287-310	36-39	120	≥7.5
N40H	1.25-1.28	12.5-12.8	≥923	≥11.6	≥1353	≥17	302-326	38-41	120	≥7.5
N42H	1.28-1.32	12.8-13.2	≥955	≥12.0	≥1353	≥17	318-342	40-43	120	≥7.5
N45H	1.32-1.36	13.2-13.6	≥963	≥12.1	≥1353	≥17	342-366	43-46	120	≥7.5
N48H	1.37-1.43	13.7-14.3	≥995	≥12.5	≥1353	≥17	366-390	46-49	120	≥7.5
N50H	1.40-1.45	14.0-14.5	≥1011	≥12.7	≥1353	≥17	382-406	48-51	120	≥7.5
N52H	1.43-1.48	14.3-14.8	≥1027	≥12.9	≥1353	≥17	398-422	50-53	120	≥7.5
N33SH	1.14-1.18	11.4-11.8	≥852	≥10.7	≥1592	≥20	247-279	31-35	150	≥7.5
N35SH	1.17-1.22	11.7-12.2	≥876	≥11.0	≥1592	≥20	263-287	33-36	150	≥7.5
N38SH	1.22-1.25	12.2-12.5	≥907	≥11.4	≥1592	≥20	287-310	36-39	150	≥7.5
N40SH	1.25-1.28	12.5-12.8	≥939	≥11.8	≥1592	≥20	302-326	38-41	150	≥7.5
N42SH	1.28-1.32	12.8-13.2	≥987	≥12.4	≥1592	≥20	318-342	40-43	150	≥7.5
N45SH	1.32-1.38	13.2-13.8	≥1003	≥12.6	≥1592	≥20	342-366	43-46	150	≥7.5
N48SH	1.37-1.43	13.7-14.3	≥1027	≥12.9	≥1592	≥20	366-390	46-49	150	≥7.5
N50SH	1.40-1.45	14.0-14.5	≥1003	≥12.6	≥1592	≥20	382-406	48-51	150	≥7.5
N28UH	1.04-1.08	10.4-10.8	≥764	≥9.6	≥1990	≥25	207-231	26-29	180	≥7.5
N30UH	1.08-1.13	10.8-11.3	≥812	≥10.2	≥1990	≥25	223-247	28-31	180	≥7.5
N33UH	1.13-1.17	11.3-11.7	≥852	≥10.7	≥1990	≥25	247-271	31-34	180	≥7.5
N35UH	1.17-1.22	11.7-12.2	≥860	≥10.8	≥1990	≥25	263-287	33-36	180	≥7.5
N38UH	1.22-1.25	12.2-12.5	≥876	≥11.0	≥1990	≥25	287-310	36-39	180	≥7.5
N40UH	1.25-1.28	12.5-12.8	≥899	≥11.3	≥1990	≥25	302-326	38-41	180	≥7.5
N42UH	1.28-1.32	12.8-13.2	≥899	≥11.3	≥1990	≥25	318-342	40-43	180	≥7.5
N45UH	1.32-1.36	13.2-13.6	≥908	≥11.4	≥1990	≥25	342-366	43-46	180	≥7.5
N48UH	1.37-1.43	13.7-14.3	≥908	≥11.4	≥1990	≥25	366-390	46-49	180	≥7.5
N28EH	1.04-1.08	10.4-10.8	≥780	≥9.8	≥2388	≥30	207-231	26-29	200	≥7.5
N30EH	1.08-1.13	10.8-11.3	≥812	≥10.2	≥2388	≥30	223-247	28-31	200	≥7.5
N33EH	1.13-1.17	11.3-11.7	≥836	≥10.5	≥2388	≥30	247-271	31-34	200	≥7.5
N35EH	1.17-1.22	11.7-12.2	≥876	≥11.0	≥2388	≥30	263-287	33-36	200	≥7.5
N38EH	1.22-1.25	12.2-12.5	≥899	≥11.3	≥2388	≥30	287-310	36-39	200	≥7.5
N40EH	1.25-1.28	12.5-12.8	≥899	≥11.3	≥2388	≥30	302-326	38-41	200	≥7.5
N42EH	1.28-1.32	12.8-13.2	≥899	≥11.3	≥2388	≥30	318-342	40-43	200	≥7.5
N45EH	1.32-1.36	13.2-13.6	≥899	≥11.3	≥2388	≥30	342-366	43-46	200	≥7.5
N28AH	1.04-1.08	10.4-10.8	≥787	≥9.9	≥2786	≥35	207-231	26-29	230	≥7.5
N30AH	1.08-1.13	10.8-11.3	≥819	≥10.3	≥2786	≥35	223-247	28-31	230	≥7.5
N33AH	1.13-1.17	11.3-11.7	≥843	≥10.6	≥2786	≥35	247-271	31-34	230	≥7.5
N35AH	1.17-1.22	11.7-12.2	≥876	≥11.0	≥2786	≥35	263-287	33-36	230	≥7.5
N38AH	1.22-1.25	12.2-12.5	≥899	≥11.3	≥2786	≥35	287-310	36-39	230	≥7.5
N40AH	1.26-1.31	12.6-13.1	≥939	≥11.8	≥2786	≥35	302-334	38-42	230	≥7.5
N42AH	1.29-1.35	12.9-13.5	≥955	≥12.0	≥2786	≥35	318-350	40-44	230	≥7.5
G48SH	1.37-1.42	13.7-14.2	>1011	>13	>1592	>20	358-390	45-49	<150	>7.5
G50SH	1.40-1.45	14.0-14.5	>1027	>13.2	>1592	>20	374-406	47-51	<150	>7.5
G52SH	1.42-1.48	14.2-14.8	>1067	>13.4	>1592	>20	390-422	49-53	<150	>7.5
G55SH	1.46-1.51	14.6-15.1	>1083	>13.6	>1592	>20	406-438	51-55	<150	>7.5
G45UH	1.33-1.38	13.3-13.8	>978	>12.4	>1990	>25	334-366	42-46	<180	>7.5
G48UH	1.37-1.42	13.7-14.2	>1027	>12.9	>1990	>25	358-390	45-49	<180	>7.5
G50UH	1.40-1.45	14.0-14.5	>1051	>13.2	>1990	>25	374-406	47-51	<180	>7.5
G52UH	1.42-1.48	14.2-14.8	>1067	>13.5	>1990	>25	390-422	49-53	<180	>7.5
G54UH	1.46-1.51	14.6-15.1	>1075	>13.5	>1990	>25	406-438	51-55	<180	>7.5
G40EH	1.26-1.31	12.6-13.1	>955	>12.0	>2388	>30	302-334	38-42	<200	>7.5
G44EH	1.29-1.35	12.6-13.1	>971	>12.2	>2388	>30	318-350	40-44	<200	>7.5
G46EH	1.33-1.38	12.6-13.1	>1011	>12.7	>2388	>30	334-366	42-46	<200	>7.5
G48EH	1.37-1.42	12.6-13.1	>1027	>12.9	>2388	>30	358-390	45-49	<200	>7.5
G50EH	1.40-1.45	12.6-13.1	>1051	>13.2	>2388	>30	374-406	47-51	<200	>7.5

Coating and Corrosion Resistance

Neodymium magnets are brittle and prone to oxidation. To protect them, most are coated with materials like:

• Nickel-Copper-Nickel (Ni-Cu-Ni) (most common)
• Epoxy
• Zinc
• Gold
• Plastic or rubber

Proper coating enhances durability, especially in humid or corrosive environments.

Choosing the Right Neodymium Magnet

When selecting a neodymium magnet, consider:

• Required magnetic strength
• Operating environment (temperature, humidity)
• Size and shape constraints
• Safety and handling (NdFeB magnets can snap together violently)

Applications of Neodymium Magnets

Some common applications include:

• Motors and generators (electric vehicles, drones)
• Magnetic resonance imaging (MRI)
• Magnetic separators
• Loudspeakers and headphones
• Hard disk drives
• Hobby and craft uses
• Magnetic therapy devices

Final Thoughts

Neodymium magnets offer unmatched power in compact sizes, but understanding their grade, magnetic properties, and temperature limits is key to using them safely and effectively. As a material expert with years in the magnet industry, I’m happy to help answer any questions or recommend the right solution for your application.

Want to Learn More?

Check out our Comprehensive Guide to Neodymium Magnet Manufacturing or contact us directly for technical support.