MW 6x6 / N38 - cylindrical magnet

Advantages and disadvantages of rare earth magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They do not lose magnetism, even after around ten years – the reduction in lifting capacity is only ~1% (theoretically),
• Magnets perfectly protect themselves against loss of magnetization caused by foreign field sources,
• The use of an aesthetic layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Magnetic induction on the working layer of the magnet is strong,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of exact forming and adapting to concrete applications,
• Fundamental importance in modern industrial fields – they are used in magnetic memories, motor assemblies, medical devices, and complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which allows their use in miniature devices

Disadvantages of neodymium magnets:

• At very strong impacts they can crack, therefore we advise placing them in special holders. A metal housing provides additional protection against damage and increases the magnet's durability.
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We suggest cover - magnetic mount, due to difficulties in realizing nuts inside the magnet and complicated shapes.
• Health risk related to microscopic parts of magnets pose a threat, in case of ingestion, which gains importance in the aspect of protecting the youngest. It is also worth noting that small elements of these magnets can complicate diagnosis medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

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

The force parameter is a measurement result conducted under the following configuration:

• on a block made of structural steel, effectively closing the magnetic field
• with a thickness no less than 10 mm
• with a plane free of scratches
• with zero gap (without paint)
• during detachment in a direction vertical to the plane
• in stable room temperature

Determinants of practical lifting force of a magnet

Effective lifting capacity is affected by working environment parameters, such as (from priority):

• Distance (betwixt the magnet and the metal), as even a tiny clearance (e.g. 0.5 mm) leads to a decrease in force by up to 50% (this also applies to paint, corrosion or dirt).
• Loading method – declared lifting capacity refers to pulling vertically. When applying parallel force, the magnet exhibits significantly lower power (typically approx. 20-30% of maximum force).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Chemical composition of the base – mild steel attracts best. Higher carbon content decrease magnetic properties and holding force.
• Surface finish – full contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Temperature influence – high temperature reduces pulling force. Too high temperature can permanently demagnetize the magnet.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, however under parallel forces the lifting capacity is smaller. Additionally, even a small distance {between} the magnet and the plate lowers the lifting capacity.