MPL 50x20x5 / N38 - lamellar magnet

Pros and cons of rare earth magnets.

Besides their immense field intensity, neodymium magnets offer the following advantages:

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (according to literature),
• Neodymium magnets prove to be remarkably resistant to loss of magnetic properties caused by external interference,
• Thanks to the shiny finish, the coating of nickel, gold-plated, or silver-plated gives an clean appearance,
• Neodymium magnets achieve maximum magnetic induction on a their surface, which allows for strong attraction,
• Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
• Thanks to modularity in forming and the ability to customize to client solutions,
• Fundamental importance in advanced technology sectors – they are utilized in hard drives, motor assemblies, advanced medical instruments, also industrial machines.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Characteristics of disadvantages of neodymium magnets and proposals for their use:

• To avoid cracks under impact, we recommend using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets suffer a drop in strength. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• Due to limitations in producing nuts and complex shapes in magnets, we recommend using a housing - magnetic mechanism.
• Health risk resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which is particularly important in the context of child safety. Furthermore, tiny parts of these devices are able to disrupt the diagnostic process medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum holding power of the magnet – what contributes to it?

The force parameter is a theoretical maximum value conducted under specific, ideal conditions:

• on a plate made of structural steel, perfectly concentrating the magnetic field
• whose transverse dimension is min. 10 mm
• with an polished touching surface
• without any clearance between the magnet and steel
• during pulling in a direction vertical to the plane
• at temperature room level

Lifting capacity in real conditions – factors

In real-world applications, the actual lifting capacity depends on several key aspects, presented from the most important:

• Gap between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to pulling vertically. When slipping, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Steel grade – ideal substrate is high-permeability steel. Cast iron may generate lower lifting capacity.
• Surface structure – the more even the surface, the better the adhesion and stronger the hold. Roughness creates an air distance.
• Thermal environment – temperature increase results in weakening of induction. Check the maximum operating temperature for a given model.

* Lifting capacity was measured by applying a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the load capacity is reduced by as much as fivefold. In addition, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.