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N35 vs N52 Magnets: Which is Stronger

Neodymium magnets are a group of materials made from rare earth minerals and utilized in a wide variety of industrial processes and applications. The first Neodymium magnet was prototyped in 1885 when Dr. Welsbach, given his expertise and keen curiosity, divided didymium into neodymium and praseodymium, two unique parts of the former rare element. Though met with little support, Dr. Welsbach’s discovery would endure transitions into different decades before being accepted by scientists almost one hundred years later. In 1982, the present-day alloy of neodymium, iron, and boron was made.

Suppose you place an N35 Neodymium magnet beside an N52 Neodymium magnet. Which of the magnets would create a stronger field? If you choose the N52 magnet, you’re certainly right. The N52 grade is one of the strongest Neodymium magnets and thus outperforms any other grade of Neodymium magnets.

How are Neodymium magnets graded?

Magnets come in different grades; in any random store that sells or ships magnets, you’d see magnets with letters and numbers that don’t always corroborate with their sizes. An N42 magnet packaged for shipping may be smaller than the SH 48 magnet you’ve just purchased, but your SH 48 magnet is certainly not as strong.

The grade assigned to any magnet measures its Maximum Energy Product, expressed in Mega Gauss Oersteds (MGOe), indicating the magnet’s strongest point on a BH curve. The higher the grade, the stronger the magnetic field generated by the magnet, which corresponds with the magnet’s inherent strength.

Why are Neodymium magnets graded?

Neodymium magnets are graded to suggest applications or processes for which a given magnet can be used. These magnets are temperature sensitive, having a maximum temperature resistance. However, some Neodymium magnets can withstand temperatures above the average range due to modifications in their formation and manufacturing; in such cases, the grades also inform users of the magnets’ unique features.

Industrial usage likewise depends on grading. Industrial processes often require the best tools or equipment at the most affordable prices. With magnets, the higher the grade – and stronger the magnet – the more inflated its gross cost. Thus, industries that frequently work with magnets decide on the specific magnet for different processes and use the strongest magnets in a few applications to conserve cost.

The “N” grade

N in magnet grading means ‘Neo,’ indicating that the magnet is made of Neodymium material. The numbers following the ‘N’ rank the magnet’s strength from weakest to strongest. In some cases, these numbers are followed by one or two letters, such as SH or EH, informing enthusiasts that the magnets in question can withstand more than the maximum temperature rating for a Neodymium magnet. If no letters follow the numbers, the magnet will function at the standard Neodymium magnet temperature.

Formulation

Neodymium magnets undergo a five-step process from mixing to coating. This process applies to all grades of magnets, including the N35 and N52 grades. Being weaker and cheaper, N35 magnets would not consume as much starting material as the N52 magnet. Neodymium magnets are composed of three elements – Neodymium, iron, and boron; to boost the magnet’s strength, some manufacturers introduce dysprosium, the most magnetic existing element, which displaces some of the Neodymium content of the magnet.

The materials are heated and mixed to form the desired alloy, cooled into ingots, and ground into tiny particles. The first phase of magnetism occurs when the smooth alloy powders are compressed into a mold as a field of magnetism is wound around the mold. However, the magnetism is stripped and later reapplied.

After demagnetizing the mold, it is heated to sinter to fuse the powdered particles, increasing the particle’s tensile strength. The obtained form is cooled before being cut into preset shapes using a diamond tool. The product can be magnetized again, though manufacturers ensure that all magnets are coated with a suitable coating mixture such as PTFE to neutralize the magnet’s brittleness.

Differences Between N35 and N52

The known properties of a magnet contribute to its overall performance. An N35 magnet differs from an N52 magnet under the scope of these properties:

Remanence

This is a measure of the residual magnetic field of a material when an external field acting on the material has been removed. A magnet’s remanence can be removed by demagnetizing it. Some industries prefer neodymium magnets with little to no remanence, given that a magnet with high remanence can trigger risky results.

An N35 magnet has a remanence of 1170 – 1220 mT. The N52 magnet has a greater remanence value of 1430 – 1480 mT and is less suitable for processes that require a magnet to be stripped of all magnetic fields when an external field is removed.

bHc

The BH curve is an expression of a magnet’s Residual Flux Density, Coercive force, and Permeance Coercivity, plotted together to derive a hysteresis curve. This feature describes the behavior of magnetic property. Based on the BH curve, an N35 magnet has a lower performance ratio than the N52 magnet based on its field strength and pull force.

iHc

Intrinsic coercive force, or iHc, defines the magnitude of a material’s magnetic field when an acting magnetic field positioned opposite the direction of the material’s field causes it to lose its magnetization. The magnetic flux generated flows towards the external field and, at some point, will make the material demagnetized.

This feature is of essential use in processes that involve a strong reverse magnetic field. The N35 magnet, at 955 kA/m, has a higher iHc than any other N-grade magnet, including the N52 type, with an intrinsic force of 876 kA/m

BH (max)

The Maximum Energy product is crucial in understanding the BH max curve, which indicates the differences in two magnets of different grades. This value isn’t dependent on a magnet’s size. The largest rectangle can be inscribed under a magnet’s Normal Curve when the magnetism is read in Gauss and the coercivity in Oersteds, yielding the unit MGOe.

The lower a magnet’s rating, the less it is BH (max). Hence, N35 has a considerably lower MGOe value than N52 magnets. Though the BH (max) implies the magnetic field force of a material, it gives no information regarding the magnetic flux or field density. Hence, it isn’t a holistic measure of a magnet’s performance.

Shapes and Dimensions

Neodymium magnets are cut into various shapes, depending on the intended application or process in which the magnets would be used. The most common shapes include circular, cylindrical, and rectangles. The dimensions are measured in millimeters; the small N52 magnet in many households has a 50mm by 5mm dimension.

Neodymium Magnet Uses

Neodymium magnets have a strong driving force. In the presence of ferromagnetic substances, high-grade magnets like the N52 can fly across a room due to the magnetic field pulling at them. In such situations, they will shatter or break any object in a collision path. They require gentle handling, as they can connect with and shatter finger bones if dropped on a finger at rest on a flat surface.

The strongest magnets aren’t always the best choice. In a sensor application, an N35 magnet may be preferred to an N52 magnet, yielding undesired results. The required pull force and magnetic field help in magnets selection.

Given their high magnetic fields and the uniqueness of their formation, Neodymium magnets are already widely used in many modern technological applications, especially ones that require a strong magnet with a permanent magnetic effect.

Some of these uses include:

  • Electric generators (N35 magnets are preferred to N52 magnets for this, given the cost disparity).
  • Locks
  • Phone speakers.
  • Design of refrigerators.
  • Electric motors.

How Other Magnets Compare to N35 & N52

All magnets grades as ‘N’ have a maximum working temperature of 80C. Being the weakest, the N35 magnet yields the least magnetic field of all ‘N’ magnets, while the N52 magnet produces the strongest. Other magnet grades include N38, N40, N42, N45, N48, and N50. Their respective BH (max) are 1220 – 1250, 1250 – 1280, 1280 – 1320, 1320 – 1380, 1380 – 1420, and 1400 – 1450 when measured in mT.

Other Grades

Neodymium magnets can also be graded into different categories based on temperature limits. The temperature affects the usability and performance of a specific magnet grade. Known temperature grades are:

  • “H,” for up to 120C. The family of magnets with the “H” grade have remanence ranging between 1080 – 1370 in mT across eight different units.
  • “SH,” up to 150C. The magnets with the “SH” grade have remanence ranging between 1080 – 1320 mT across seven different units.
  • “UH,” up to 180C. The family of magnets with the “UH” grade have remanence ranging between 1020 – 1250 in mT across six different units.
  • “EH,” up to 200C. The family of magnets with the “EH” grade have remanence ranging between 1040 – 1220 in mT across five different units.

Conclusion

From the values supplied above, we can deduce that the higher the temperature a neodymium magnet can withstand, the lower its remanence. The highest-graded ‘normal’ neodymium magnet has a remanence of 1480 mT, performing well above any other temperature-driven grade.

However, the best magnets aren’t always the strongest ones. Before deciding on a purchase, consult a technician to learn the right neodymium magnets for your predetermined process or procedure.

Where to Buy

At ROBO Magnetic, we ship and deliver the most refined neodymium magnets in swift time, getting you all set up within one week of receiving your order. To get started, fill out a request form, and we’ll take it over from there.

 

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Article by

ROBO Magnetic Product Team

We are the manufacturer with 16 years of experience in custom neodymium magnets.

Need A Quote? Get in touch with us directly.

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