MPL 30x15x2 / N38 - lamellar magnet

Advantages as well as disadvantages of neodymium magnets NdFeB.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They retain their full power for almost ten years – the drop is just ~1% (according to analyses),
• They remain magnetized despite exposure to strong external fields,
• By applying a shiny layer of silver, the element gains a modern look,
• They possess intense magnetic force measurable at the magnet’s surface,
• Neodymium magnets are known for very high magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the geometry),
• The ability for accurate shaping as well as customization to specific needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which extends the scope of their use cases,
• Key role in new technology industries – they find application in HDDs, electric motors, medical equipment along with other advanced devices,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are fragile when subjected to a sudden impact. If the magnets are exposed to mechanical hits, it is advisable to use in a protective case. The steel housing, in the form of a holder, protects the magnet from cracks and additionally strengthens its overall resistance,
• Magnets lose power when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (influenced by the magnet’s profile). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• They rust in a damp environment. If exposed to rain, we recommend using waterproof magnets, such as those made of polymer,
• The use of a protective casing or external holder is recommended, since machining internal cuts in neodymium magnets is risky,
• Health risk linked to microscopic shards may arise, if ingested accidentally, which is significant in the context of child safety. Additionally, tiny components from these assemblies can interfere with diagnostics once in the system,
• High unit cost – neodymium magnets are more expensive than other types of magnets (e.g., ferrite), which may limit large-scale applications

Detachment force of the magnet in optimal conditions – what affects it?

The given pulling force of the magnet corresponds to the maximum force, determined under optimal conditions, that is:

• with the use of low-carbon steel plate acting as a magnetic yoke
• having a thickness of no less than 10 millimeters
• with a refined outer layer
• in conditions of no clearance
• under perpendicular detachment force
• in normal thermal conditions

What influences lifting capacity in practice

In practice, the holding capacity of a magnet is affected by the following aspects, from crucial to less important:

• Air gap between the magnet and the plate, because even a very small distance (e.g. 0.5 mm) can cause a drop in lifting force of up to 50%.
• Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
• Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
• Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
• Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
• Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, however under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a small distance {between} the magnet and the plate reduces the load capacity.