NCM 30x13.5x5 / N38 - channel magnetic holder

Advantages as well as disadvantages of rare earth magnets.

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

• They do not lose strength, even during nearly 10 years – the reduction in power is only ~1% (based on measurements),
• They do not lose their magnetic properties even under strong external field,
• By covering with a lustrous coating of silver, the element gains an aesthetic look,
• The surface of neodymium magnets generates a concentrated magnetic field – this is a distinguishing feature,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of exact creating as well as adjusting to atypical conditions,
• Key role in advanced technology sectors – they find application in magnetic memories, brushless drives, medical equipment, and complex engineering applications.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: weaknesses and usage proposals

• To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• We recommend a housing - magnetic holder, due to difficulties in creating nuts inside the magnet and complicated shapes.
• Possible danger to health – tiny shards of magnets pose a threat, in case of ingestion, which gains importance in the context of child safety. Furthermore, tiny parts of these devices can disrupt the diagnostic process medical after entering the body.
• With mass production the cost of neodymium magnets is economically unviable,

Maximum lifting force for a neodymium magnet – what it depends on?

Information about lifting capacity was determined for ideal contact conditions, assuming:

• with the contact of a sheet made of special test steel, guaranteeing maximum field concentration
• possessing a massiveness of min. 10 mm to avoid saturation
• characterized by lack of roughness
• with zero gap (without coatings)
• during pulling in a direction perpendicular to the mounting surface
• at temperature room level

Determinants of practical lifting force of a magnet

During everyday use, the actual lifting capacity depends on several key aspects, presented from crucial:

• Space between surfaces – every millimeter of distance (caused e.g. by varnish or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Steel grade – ideal substrate is high-permeability steel. Stainless steels may have worse magnetic properties.
• Surface structure – the more even the surface, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Temperature – temperature increase results in weakening of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was determined using a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under shearing force the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet’s surface and the plate reduces the load capacity.