Neodymium magnets are graded according to their maximum energy product, which relates to the magnetic flux output per unit volume. Higher values indicate stronger magnets. For sintered NdFeB magnets, there is a widely recognized international classification. Their values range from 28 up to 52. The right part “letter” reflects level of intrinsic coercivity Hcj. The levels include “M” (Hcj ≥ 14 kOe), “H” (Hcj ≥ 17 kOe), “SH” (Hcj ≥ 20 kOe), “UH” (Hcj ≥ 25 kOe), “EH” (Hcj ≥ 30 kOe) and “AH” (Hcj ≥ 35 kOe), they are abbreviations for “Medium”, “High”, “Super High”, “Ultra High”, “Extreme High” and “Abnormal High”,  The first letter N before the values is short for neodymium, meaning sintered NdFeB magnets. Letters following the values indicate intrinsic coercivity and maximum operating temperatures (positively correlated with the Curie temperature), which range from default (up to 80 °C or 176 °F) to AH (230 °C or 446 °F)

1.Neodymium Magnets N52 vs N35

The key difference is that their (BH)max are 35 MGOe and 52 MGOe, respectively. As a permanent magnet’s remanence Br is closely linked to its (BH)max, it also means that the N35 magnet’s Br is lower than that of the N52 magnet, i.e. the latter has higher magnetic flux density. As results, a motor or device using N52 magnet can have higher power and/or can become smaller/lighter than that using N35 magnet.

As N35 and N52 magnets both are sintered NdFeB magnets, why do they have so huge difference in (BH)max? Is it a quality issue? The answer is absolutely not. It should be noted that the grade classification of permanent magnets is only based on their magnetic properties, it has nothing to do with quality. A specific grade is a macro performance resulting from material composition and microstructure. In order to achieve a required grade or relative magnetic properties, it can be manipulated and controlled via material ingredients and production process.

Although N52 magnets have extremely high (BH)max at room temperature, currently the top level among commercial magnets, they are used in a few applications due to their high cost (around 50% higher than that of N35 magnets). Actually N35 magnets are the most widely used in various applications among sintered NdFeB magnets. Compared with other permanent magnets such ceramic/ferrite magnets, typical (BH)max around 4 MGOe, N35 magnets have nearly 8-9 times stronger power. In some cases, it really needs NdFeB magnets with higher (BH)max, N45, N48 and N50 magnets are already strong enough. Via structure design and optimization, using these grade magnets instead of N52 magnets are able to meet target performances at lower costs.

2.Neodymium Magnets N52 vs N50

A neodymium magnet N52 is the strongest magnet for the same size among all the permanent neodymium magnets on the market. All the N52 neodymium magnets provide the highest Maximum Energy Product no matter their sizes or shapes.

STRENGTHS REPRESENTED: NEODYMIUM N52 WITH PULLING FORCE UP TO OVER 600LBS.

The 50 neodymium magnets are the second highest grade & of the same highest quality permanent neodymium magnets on the market. All the N50 neodymium magnets provide the same 50 MGOe (science stuff) as the High Energy Rare Earth Magnets, no matter their sizes or shapes. Shapes: Bar Magnets, Cube Magnets, Disc Magnets, Rings & Sphere Magnets.  Many available with plastic or epoxy coatings. Types: Standard, Countersunk (round & rectangular)

STRENGTHS REPRESENTED: NEODYMIUM N50 WITH PULLING FORCE UP TO OVER 450LBS.

3.Neodymium Magnets N52 vs N48/Neodymium Magnets N42 vs N52 ...

Please see the table below