MW 6x6 / N38 - cylindrical magnet

Advantages as well as disadvantages of neodymium magnets.

Apart from their strong magnetic energy, neodymium magnets have these key benefits:

• They do not lose magnetism, even during around 10 years – the reduction in strength is only ~1% (theoretically),
• They are noted for resistance to demagnetization induced by external field influence,
• The use of an refined coating of noble metals (nickel, gold, silver) causes the element to present itself better,
• Magnetic induction on the surface of the magnet remains exceptional,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling action at temperatures reaching 230°C and above...
• Thanks to the option of accurate shaping and adaptation to individualized requirements, magnetic components can be modeled in a wide range of shapes and sizes, which expands the range of possible applications,
• Key role in innovative solutions – they find application in hard drives, motor assemblies, medical devices, and complex engineering applications.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• At very strong impacts they can crack, 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 decrease their strength 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
• They oxidize in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited possibility of making nuts in the magnet and complicated shapes - recommended is a housing - magnet mounting.
• Possible danger to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the context of child safety. It is also worth noting that tiny parts of these magnets are able to disrupt the diagnostic process medical in case of swallowing.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Maximum lifting force for a neodymium magnet – what affects it?

The load parameter shown concerns the maximum value, recorded under laboratory conditions, namely:

• on a block made of structural steel, effectively closing the magnetic field
• possessing a massiveness of minimum 10 mm to avoid saturation
• with an ideally smooth contact surface
• with direct contact (no paint)
• during pulling in a direction perpendicular to the plane
• at temperature room level

Lifting capacity in real conditions – factors

Holding efficiency impacted by specific conditions, including (from most important):

• Air gap (betwixt the magnet and the plate), because even a very small clearance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
• Loading method – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet holds much less (often approx. 20-30% of maximum force).
• Steel thickness – insufficiently thick steel causes magnetic saturation, causing part of the flux to be lost into the air.
• Material type – the best choice is high-permeability steel. Hardened steels may generate lower lifting capacity.
• Surface finish – ideal contact is possible only on polished steel. Rough texture create air cushions, reducing force.
• Thermal factor – high temperature reduces pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was carried out on a smooth plate of optimal thickness, under perpendicular forces, whereas under shearing force the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate reduces the holding force.