MPL 40x10x4 / N38 - lamellar magnet

Strengths and weaknesses of rare earth magnets.

Besides their exceptional field intensity, neodymium magnets offer the following advantages:

• Their magnetic field is maintained, and after approximately 10 years it decreases only by ~1% (theoretically),
• They possess excellent resistance to weakening of magnetic properties as a result of external magnetic sources,
• In other words, due to the metallic surface of gold, the element gains a professional look,
• Magnets possess exceptionally strong magnetic induction on the outer layer,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Possibility of exact modeling and adapting to complex needs,
• Versatile presence in future technologies – they are utilized in hard drives, electromotive mechanisms, medical equipment, and complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets and proposals for their use:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting 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 power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Limited ability of producing nuts in the magnet and complicated forms - recommended is cover - magnetic holder.
• Health risk resulting from small fragments of magnets are risky, in case of ingestion, which gains importance in the context of child health protection. Furthermore, tiny parts of these products are able to be problematic in diagnostics medical when they are in the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

Optimal lifting capacity of a neodymium magnet – what affects it?

The load parameter shown concerns the peak performance, measured under optimal environment, namely:

• with the contact of a sheet made of special test steel, ensuring full magnetic saturation
• whose thickness is min. 10 mm
• with a plane free of scratches
• without the slightest clearance between the magnet and steel
• for force acting at a right angle (in the magnet axis)
• at ambient temperature approx. 20 degrees Celsius

Key elements affecting lifting force

Effective lifting capacity is influenced by working environment parameters, including (from most important):

• Gap between surfaces – even a fraction of a millimeter of distance (caused e.g. by varnish or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Plate thickness – too thin steel causes magnetic saturation, causing part of the power to be wasted to the other side.
• Steel type – low-carbon steel attracts best. Alloy steels reduce magnetic properties and holding force.
• Surface condition – ground elements guarantee perfect abutment, which improves force. Uneven metal weaken the grip.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. When it is hot they are weaker, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the load capacity.