MPL 50x20x5 / N38 - lamellar magnet

Strengths as well as weaknesses of rare earth magnets.

Apart from their consistent power, neodymium magnets have these key benefits:

• They retain attractive force for almost 10 years – the drop is just ~1% (based on simulations),
• Neodymium magnets prove to be highly resistant to demagnetization caused by external magnetic fields,
• By using a reflective coating of gold, the element gains an aesthetic look,
• Neodymium magnets create maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures approaching 230°C and above...
• In view of the option of accurate molding and adaptation to custom solutions, magnetic components can be produced in a wide range of forms and dimensions, which amplifies use scope,
• Significant place in electronics industry – they are used in magnetic memories, motor assemblies, advanced medical instruments, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which enables their usage in miniature devices

Disadvantages of neodymium magnets:

• At strong impacts they can crack, therefore we advise placing them in strong housings. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (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 extremely resistant to heat
• They rust in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We suggest a housing - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complex forms.
• Potential hazard resulting from small fragments of magnets pose a threat, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products are able to be problematic in diagnostics medical when they are in 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 is the result of a measurement for ideal contact conditions, including:

• with the use of a sheet made of special test steel, guaranteeing maximum field concentration
• whose transverse dimension equals approx. 10 mm
• with an ideally smooth touching surface
• without any air gap between the magnet and steel
• during pulling in a direction perpendicular to the plane
• in neutral thermal conditions

Impact of factors on magnetic holding capacity in practice

Please note that the application force will differ depending on the following factors, in order of importance:

• Distance – existence of foreign body (paint, tape, air) interrupts the magnetic circuit, which reduces power rapidly (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to detachment vertically. When slipping, the magnet holds much less (typically approx. 20-30% of maximum force).
• Plate thickness – too thin steel causes magnetic saturation, causing part of the power to be lost into the air.
• Steel grade – ideal substrate is pure iron steel. Cast iron may attract less.
• Surface structure – the more even the surface, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Thermal conditions – NdFeB sinters have a sensitivity to temperature. At higher temperatures they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity was determined with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the load capacity.