NCM 15x13.5x5 / N38 - channel magnetic holder

Pros and cons of rare earth magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• They virtually do not lose power, because even after ten years the performance loss is only ~1% (according to literature),
• Neodymium magnets are highly resistant to magnetic field loss caused by magnetic disturbances,
• Thanks to the reflective finish, the plating of Ni-Cu-Ni, gold, or silver-plated gives an clean appearance,
• The surface of neodymium magnets generates a concentrated magnetic field – this is one of their assets,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Considering the possibility of flexible forming and customization to unique needs, neodymium magnets can be created in a broad palette of forms and dimensions, which increases their versatility,
• Versatile presence in modern technologies – they find application in data components, electromotive mechanisms, precision medical tools, also multitasking production systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a special holder, which not only secures them against impacts but also increases their durability
• Neodymium magnets lose their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• We suggest a housing - magnetic mechanism, due to difficulties in realizing threads inside the magnet and complex forms.
• Health risk to health – tiny shards of magnets are risky, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Furthermore, tiny parts of these products can disrupt the diagnostic process medical in case of swallowing.
• With budget limitations the cost of neodymium magnets is economically unviable,

Best holding force of the magnet in ideal parameters – what it depends on?

Information about lifting capacity is the result of a measurement for the most favorable conditions, assuming:

• on a base made of mild steel, effectively closing the magnetic field
• whose transverse dimension is min. 10 mm
• characterized by smoothness
• under conditions of gap-free contact (surface-to-surface)
• during detachment in a direction perpendicular to the plane
• in neutral thermal conditions

Lifting capacity in real conditions – factors

During everyday use, the actual holding force results from several key aspects, ranked from crucial:

• Distance – the presence of any layer (paint, dirt, gap) acts as an insulator, which lowers power rapidly (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.
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Steel grade – ideal substrate is high-permeability steel. Hardened steels may have worse magnetic properties.
• Plate texture – smooth surfaces ensure maximum contact, which increases force. Rough surfaces reduce efficiency.
• Heat – NdFeB sinters have a negative temperature coefficient. At higher temperatures they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under parallel forces the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the holding force.