MW 6x2 / N38 - cylindrical magnet

Advantages and disadvantages of neodymium magnets.

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

• They do not lose magnetism, even during nearly ten years – the reduction in strength is only ~1% (theoretically),
• Magnets perfectly defend themselves against loss of magnetization caused by external fields,
• Thanks to the shiny finish, the coating of Ni-Cu-Ni, gold, or silver gives an elegant appearance,
• 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...
• Thanks to flexibility in designing and the ability to modify to complex applications,
• Fundamental importance in electronics industry – they serve a role in magnetic memories, drive modules, medical devices, and technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

What to avoid - cons of neodymium magnets and ways of using them

• At strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage, as well as 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 power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• Due to limitations in creating threads and complicated shapes in magnets, we propose using casing - magnetic holder.
• Potential hazard resulting from small fragments of magnets pose a threat, in case of ingestion, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small elements of these devices are able to disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which hinders application in large quantities

Maximum lifting capacity of the magnet – what affects it?

The declared magnet strength concerns the limit force, measured under ideal test conditions, namely:

• on a block made of structural steel, perfectly concentrating the magnetic flux
• whose thickness reaches at least 10 mm
• with an ideally smooth contact surface
• under conditions of ideal adhesion (surface-to-surface)
• during detachment in a direction vertical to the mounting surface
• at temperature room level

Practical aspects of lifting capacity – factors

In real-world applications, the actual holding force is determined by a number of factors, ranked from most significant:

• Distance – the presence of any layer (paint, dirt, gap) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to detachment vertically. When applying parallel force, the magnet holds significantly lower power (often approx. 20-30% of nominal force).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Plate material – low-carbon steel gives the best results. Alloy steels reduce magnetic permeability and holding force.
• Base smoothness – the more even the surface, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Temperature – heating the magnet results in weakening of force. Check the maximum operating temperature for a given model.

* Holding force was checked on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under shearing force the holding force is lower. In addition, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.