MPL 40x18x10 SH / N38 - lamellar magnet

Strengths as well as weaknesses of NdFeB magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They do not lose strength, even over approximately 10 years – the drop in strength is only ~1% (according to tests),
• Magnets very well protect themselves against demagnetization caused by ambient magnetic noise,
• Thanks to the shimmering finish, the plating of Ni-Cu-Ni, gold-plated, or silver-plated gives an aesthetic appearance,
• Neodymium magnets create maximum magnetic induction on a contact point, which allows for strong attraction,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for operation at temperatures reaching 230°C and above...
• In view of the potential of free molding and customization to unique needs, magnetic components can be created in a variety of geometric configurations, which expands the range of possible applications,
• Key role in advanced technology sectors – they are commonly used in hard drives, drive modules, diagnostic systems, as well as complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which enables their usage in compact constructions

Disadvantages of neodymium magnets:

• At strong impacts they can break, therefore we recommend placing them in special holders. A metal housing provides additional protection against damage and increases the magnet's 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 durability even at temperatures up to 230°C
• They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing threads and complex forms in magnets, we recommend using a housing - magnetic holder.
• Possible danger related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child safety. Additionally, tiny parts of these magnets are able to disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which can limit application in large quantities

Maximum lifting capacity of the magnet – what affects it?

The load parameter shown represents the limit force, recorded under ideal test conditions, namely:

• using a sheet made of mild steel, acting as a magnetic yoke
• possessing a massiveness of minimum 10 mm to avoid saturation
• with a plane free of scratches
• without the slightest clearance between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• in neutral thermal conditions

Impact of factors on magnetic holding capacity in practice

Please note that the magnet holding may be lower subject to the following factors, starting with the most relevant:

• Distance (betwixt the magnet and the metal), because even a very small clearance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to paint, rust or debris).
• Load vector – maximum parameter is available only during perpendicular pulling. The shear force of the magnet along the plate is standardly many times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Metal type – not every steel reacts the same. Alloy additives worsen the attraction effect.
• Base smoothness – the more even the plate, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Temperature influence – hot environment weakens pulling force. Too high temperature can permanently damage the magnet.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under attempts to slide the magnet the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate decreases the load capacity.