MPL 40x18x10 / N38 - lamellar magnet

Strengths and weaknesses of rare earth magnets.

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

• They retain magnetic properties for around ten years – the drop is just ~1% (according to analyses),
• Neodymium magnets are characterized by highly resistant to loss of magnetic properties caused by external magnetic fields,
• By covering with a smooth coating of nickel, the element acquires an nice look,
• The surface of neodymium magnets generates a concentrated magnetic field – this is one of their assets,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Possibility of detailed forming as well as adjusting to individual requirements,
• Key role in electronics industry – they serve a role in mass storage devices, electromotive mechanisms, medical devices, also complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer high power in compact dimensions, which allows their use in compact constructions

Problematic aspects of neodymium magnets: weaknesses and usage proposals

• At very strong impacts they can break, therefore we advise placing them in special holders. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets lose power when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (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
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Due to limitations in producing threads and complicated forms in magnets, we propose using casing - magnetic mechanism.
• Possible danger related to microscopic parts of magnets can be dangerous, if swallowed, which becomes key in the aspect of protecting the youngest. Additionally, tiny parts of these products can disrupt the diagnostic process medical in case of swallowing.
• Due to expensive raw materials, their price exceeds standard values,

Maximum magnetic pulling force – what affects it?

The load parameter shown concerns the limit force, measured under laboratory conditions, namely:

• on a plate made of structural steel, effectively closing the magnetic field
• with a thickness no less than 10 mm
• with a plane free of scratches
• with total lack of distance (no paint)
• for force applied at a right angle (in the magnet axis)
• in stable room temperature

Key elements affecting lifting force

In real-world applications, the real power results from several key aspects, listed from crucial:

• Gap (betwixt the magnet and the plate), since even a very small distance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to varnish, rust or dirt).
• Force direction – note that the magnet holds strongest perpendicularly. Under sliding down, the holding force 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.
• Steel type – low-carbon steel attracts best. Alloy steels reduce magnetic properties and lifting capacity.
• Surface finish – ideal contact is obtained only on polished steel. Any scratches and bumps create air cushions, reducing force.
• Thermal factor – high temperature reduces magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity was determined using a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, however under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet and the plate reduces the holding force.