MPL 200x30x30 / N38 - lamellar magnet

Advantages and disadvantages of neodymium magnets.

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

• They retain full power for nearly 10 years – the loss is just ~1% (according to analyses),
• They maintain their magnetic properties even under external field action,
• In other words, due to the aesthetic surface of nickel, the element gains a professional look,
• The surface of neodymium magnets generates a powerful magnetic field – this is a distinguishing feature,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of custom forming as well as adjusting to specific applications,
• Versatile presence in future technologies – they are utilized in mass storage devices, brushless drives, medical devices, and modern systems.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which allows their use in miniature devices

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also increases its resistance to damage
• Neodymium magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as 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
• 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
• Due to limitations in realizing threads and complex forms in magnets, we recommend using casing - magnetic mechanism.
• Potential hazard resulting from small fragments of magnets pose a threat, if swallowed, which is particularly important in the aspect of protecting the youngest. Furthermore, tiny parts of these products are able to complicate diagnosis medical after entering the body.
• With budget limitations the cost of neodymium magnets is a challenge,

Maximum magnetic pulling force – what contributes to it?

The specified lifting capacity concerns the limit force, recorded under optimal environment, specifically:

• on a plate made of mild steel, effectively closing the magnetic flux
• possessing a thickness of at least 10 mm to avoid saturation
• characterized by smoothness
• under conditions of gap-free contact (surface-to-surface)
• under axial force vector (90-degree angle)
• at standard ambient temperature

Determinants of practical lifting force of a magnet

Holding efficiency is affected by working environment parameters, such as (from most important):

• Space between surfaces – every millimeter of separation (caused e.g. by varnish or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – highest force is reached only during pulling at a 90° angle. The force required to slide of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Material composition – different alloys attracts identically. High carbon content weaken the attraction effect.
• Surface finish – ideal contact is possible only on smooth steel. Rough texture reduce the real contact area, reducing force.
• Operating temperature – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and in frost they can be stronger (up to a certain limit).

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under shearing force the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet and the plate reduces the holding force.