NC NeoCube fi 5 mm kuleczki kolorowe / N38 - neocube

Strengths and weaknesses of NdFeB magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They have constant strength, and over nearly ten years their attraction force decreases symbolically – ~1% (in testing),
• Neodymium magnets remain highly resistant to loss of magnetic properties caused by external field sources,
• In other words, due to the glossy surface of silver, the element looks attractive,
• Neodymium magnets generate maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of custom shaping and adjusting to individual applications,
• Fundamental importance in future technologies – they are commonly used in mass storage devices, brushless drives, medical devices, as well as modern systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• They oxidize in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing threads and complicated shapes in magnets, we propose using casing - magnetic mount.
• Potential hazard related to microscopic parts of magnets can be dangerous, if swallowed, which gains importance in the context of child health protection. Furthermore, small components of these products are able to be problematic in diagnostics medical after entering the body.
• With mass production the cost of neodymium magnets is economically unviable,

Maximum lifting capacity of the magnet – what contributes to it?

The force parameter is a theoretical maximum value performed under the following configuration:

• on a plate made of mild steel, effectively closing the magnetic flux
• with a thickness of at least 10 mm
• characterized by even structure
• with total lack of distance (without paint)
• for force acting at a right angle (pull-off, not shear)
• at conditions approx. 20°C

Determinants of lifting force in real conditions

Effective lifting capacity impacted by specific conditions, such as (from most important):

• Clearance – existence of any layer (rust, dirt, gap) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Plate thickness – too thin steel does not close the flux, causing part of the power to be lost into the air.
• Metal type – different alloys reacts the same. High carbon content weaken the attraction effect.
• Surface finish – full contact is obtained only on polished steel. Any scratches and bumps create air cushions, reducing force.
• Operating temperature – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under attempts to slide the magnet the holding force is lower. In addition, even a small distance {between} the magnet’s surface and the plate reduces the holding force.