MW 14.9x10 / N38 - cylindrical magnet

Pros as well as cons of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They retain magnetic properties for almost ten years – the drop is just ~1% (in theory),
• Neodymium magnets prove to be exceptionally resistant to magnetic field loss caused by external field sources,
• Thanks to the reflective finish, the layer of nickel, gold, or silver-plated gives an visually attractive appearance,
• Magnets are distinguished by very high magnetic induction on the active area,
• Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of precise creating as well as optimizing to atypical needs,
• Wide application in future technologies – they are used in computer drives, motor assemblies, medical devices, and multitasking production systems.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

What to avoid - cons of neodymium magnets and ways of using them

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a steel housing, which not only protects them against impacts but also increases their durability
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation and corrosion.
• Due to limitations in creating threads and complicated forms in magnets, we propose using a housing - magnetic holder.
• Potential hazard resulting from small fragments of magnets can be dangerous, in case of ingestion, which becomes key in the aspect of protecting the youngest. It is also worth noting that small components of these magnets can be problematic in diagnostics medical in case of swallowing.
• With large orders the cost of neodymium magnets is a challenge,

Optimal lifting capacity of a neodymium magnet – what it depends on?

The load parameter shown refers to the maximum value, measured under laboratory conditions, namely:

• on a base made of mild steel, optimally conducting the magnetic field
• with a cross-section of at least 10 mm
• with a surface cleaned and smooth
• without any insulating layer between the magnet and steel
• under perpendicular application of breakaway force (90-degree angle)
• in neutral thermal conditions

Practical aspects of lifting capacity – factors

It is worth knowing that the working load may be lower influenced by the following factors, starting with the most relevant:

• Clearance – the presence of foreign body (rust, tape, air) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Material composition – different alloys reacts the same. High carbon content weaken the interaction with the magnet.
• Surface quality – the more even the surface, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
• Operating temperature – NdFeB sinters have a sensitivity to temperature. At higher temperatures they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was conducted on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, in contrast under parallel forces the lifting capacity is smaller. In addition, even a small distance {between} the magnet and the plate reduces the lifting capacity.