MW 29x10 / N38 - cylindrical magnet

Pros and cons of rare earth magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They have constant strength, and over nearly ten years their performance decreases symbolically – ~1% (according to theory),
• Neodymium magnets prove to be extremely resistant to demagnetization caused by external interference,
• In other words, due to the aesthetic layer of nickel, the element becomes visually attractive,
• Neodymium magnets ensure maximum magnetic induction on a contact point, which ensures high operational effectiveness,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures reaching 230°C and above...
• Possibility of custom machining and optimizing to concrete requirements,
• Versatile presence in modern technologies – they serve a role in data components, brushless drives, precision medical tools, and modern systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are fragile upon heavy impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only shields the magnet but also improves its resistance to damage
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 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 and corrosion.
• Due to limitations in creating threads and complicated forms in magnets, we recommend using cover - magnetic mechanism.
• Possible danger resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that small elements 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 can limit application in large quantities

Optimal lifting capacity of a neodymium magnet – what contributes to it?

The force parameter is a result of laboratory testing executed under standard conditions:

• on a base made of structural steel, effectively closing the magnetic field
• with a thickness no less than 10 mm
• with a surface free of scratches
• without any insulating layer between the magnet and steel
• under perpendicular application of breakaway force (90-degree angle)
• at temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

Please note that the magnet holding will differ influenced by elements below, starting with the most relevant:

• Air gap (betwixt the magnet and the metal), because even a very small clearance (e.g. 0.5 mm) results in a drastic drop in force by up to 50% (this also applies to varnish, rust or debris).
• Loading method – declared lifting capacity refers to pulling vertically. When slipping, the magnet exhibits significantly lower power (often approx. 20-30% of maximum force).
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Metal type – not every steel attracts identically. Alloy additives weaken the interaction with the magnet.
• Surface quality – the more even the surface, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and in frost they can be stronger (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under perpendicular forces, in contrast under parallel forces the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet and the plate lowers the lifting capacity.