Neodymium Magnets

An Introduction to Neodymium Magnets

Neodymium Iron Boron ("Neo", NdFeB or Neodymium) Magnets are made from an alloy containing, amongst others, the elements Neodymium, Iron and Boron (NdFeB). The NdFeB magnets are the strongest type of magnet commercially available and are manufactured in a wide range of shapes, sizes and grades. We offer 50 grades of licensed standard corrosion resistance Neodymium Iron Boron and now an additional 57 grades of improved corrosion resistance Neodymium Iron Boron, each type with 25 types of coating finish for each grade (107 grades in total with 25 finishes - 2675 combinations).

The NdFeB magnets are anisotropic sintered magnets – the alloy is jet milled to a fine powder and is then compacted in the presence of a magnetic field to give it a preferred direction of magnetisation. The NdFeB magnets are then sintered to fuse the powder together before final machining and magnetising produces the completed super strength Neodymium magnet.

The Neodymium magnets are also known as Neo magnets, Neodymium Iron Boron magnets, Neodymium-Iron-Boron magnets, NdBFe magnets, NdFeB magnets, NIB magnets, Super Strength magnets and Rare Earth magnets (please note that SmCo is also called a Rare Earth magnet). NdFeB is called a Rare Earth magnet because the Neodymium is a Rare Earth element, having a value of 60 on the Periodic Table. For note, there is nothing rare about Rare Earth magnets – the required elements are readily available and the NdFeB magnets are produced in several hundreds of tonnes each year.

The Neodymium Iron Boron (NdFeB) magnets were developed just over 25 years ago and were first commercially available in 1984. Neodymium magnets were initially developed for voice coil motors in computer hard disk drives and this market still accounts for over 50 percent of all Neodymium magnets produced. Other applications include high performance motors, brushless DC motors, generators, magnetic separation, magnetic resonance imaging, sensors and loudspeakers. They are becoming increasingly popular across a wide range of novelty products such as fridge magnets and all kinds of magnetically attachable gadgets for retail markets.

For note, our standard NdFeB is rated to +80 deg C. We offer the whole range of Neodymium Iron Boron magnets, with Maximum Energy Product (BHmax) ratings from 27 MGOe to 52 MGOe (N27 to N52) and with a maximum operating temperature rating ranging from +60/+80 deg C to +220/+230 deg C (Nxx up to NxxVH / NxxAH, where xx is the Maximum Energy Product in MGOe). The complete standard corrosion resistance range of grades is as follows:-
N27, N30, N33, N35, N38, N40, N42, N45, N48, N50, N52, N30M, N33M, N35M, N38M, N40M, N42M, N45M, N48M, N50M, N30H, N33H, N35H, N38H, N40H, N42H, N45H, N48H, N30SH, N33SH, N35SH, N38SH, N40SH, N42SH, N45SH, N28UH, N30UH, N33UH, N35UH, N38UH, N40UH, N28EH, N30EH, N33EH, N35EH, N38EH, N28VH/AH, N30VH/AH, N33VH/AH, N35VH/AH.

The complete improved corrosion resistance range of grades is as follows:-
N27T, N30T, N33T, N35T, N38T, N40T, N42T, N45T, N48T, N50T, N52T, N30MT, N33MT, N35MT, N38MT, N40MT, N42MT, N45MT, N48MT, N50MT, N30HT, N33HT, N35HT, N38HT, N40HT, N42HT, N45HT, N48HT, N30SHT, N33SHT, N35SHT, N38SHT, N40SHT, N42SHT, N45SHT, L-N30SHT, L-N33SHT, L-N35SHT, L-N38SHT, L-N40SHT, L-N42SHT, L-N45SHT L-N28UHT, L-N30UHT, L-N33UHT, L-N35UHT, L-N38UHT, L-N40UHT, L-N28EHT, L-N30EHT, L-N33EHT, L-N35EHT, L-N38EHT, L-N28VHT/AHT, L-N30VHT/AHT, L-N33VHT/AHT, L-N35VHT/AHT

For note, the L-NxxT versions offer the best corrosion resistance. Both the NxxT and L-NxxT versions are recent improvements and some grades may still be at late R&D stages which may affect mass production level availability. These versions are more expensive - please contact us for a quotation. Also, for maximum corrosion protection with strong magnetic performance, SmCo is a better choice.

Neodymium-Iron-Boron magnets contain approximately 75% iron and are therefore prone to corrosion. Protective coatings are applied to Neo magnets and the most common one is electroless nickel plating (Ni-Cu-Ni; effectively a triple coating). The current range of coatings available are as follows:-
Nickel-Copper-Nickel (Ni-Cu-Ni) [standard], Nickel (Ni), Epoxy, Zinc (Zn), Gold (Au), Silver (Ag), Tin (Sn), Titanium (Ti), Titanium Nitride (TiN), Parylene C, Everlube, Chrome, PTFE ("Teflon"; white, black, grey, silvery) , Ni-Cu-Ni plus Epoxy, Ni-Cu-Ni plus Rubber, Zn plus Rubber, Ni-Cu-Ni plus Parylene C, Ni-Cu-Ni plus PTFE, Tin (Sn) plus Parylene C, Zinc Chromate, Phosphate Passivation and Uncoated (i.e. bare – not recommended but is sometimes required by the customer). Other coatings may be possible - please let us know your requirements.

Apart from offering over 2675 combinations of NdFeB grade and finish, we also manufacture bespoke NdFeB sizes upon request. The NdFeB magnets vary from D1mm x 1mmA discs up to e.g. 200mm x 130mm x 25mmA blocks. Standard NdFeB tolerances are +/-0.1mm. +/-0.05mm tolerances are also available for these Neodymium Iron Boron magnets. We can produce smaller Neodymium magnets down to +/-0.005mm tolerances as part of our bespoke Precision NdFeB range (we would specify the tolerance that could be achieved for each shape but please note that the production runs would be subject to 100k minimum order quantity).

The NdFeB (NIB) magnets, in disc and ring forms, are usually axially magnetised (the round ends are the magnet poles). Diametrically magnetised discs and rings can be produced upon request (looking at the circular end face, the magnetism runs from the 12 o’clock position to the 6 o’clock position in diametrically magnetised magnets). Likewise, the rectangular blocks can be specially produced to be magnetised in any of the three axes (the magnets cannot be re-magnetised in another axis due to the method of production – the sintered NdFeB is anisotropic). Arcs, trapezoids and other shapes can generally also be produced. Bespoke Directions of Magnetisation within the magnet shape may also be possible (subject to confirmation) e.g. for Halbach Array assemblies.

If you require a bespoke Neodymium Iron Boron (NdFeB, NIB, Neodymium, Neo) magnet or magnetic assembly, Technical Support or our NdFeB Technical Data Sheet, please contact us.

Types of Neodymium Magnets

Circular Disc Magnets
Adhesive Backed Discs
Ring Magnets
Rectangular Magnets
Adhesives
Spheres
Rod Magnets
Neo Pot Magnets
Variety Packs
Magnetic Retrieval Pen
NdFeB Halbach Array
Precision NdFeB Magnets

How to buy Neodymium Magnets

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