MPL 40x15x5x2[7/3.5] / N38 - lamellar magnet

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They virtually do not lose power, because even after 10 years, the decline in efficiency is only ~1% (according to literature),
• They protect against demagnetization induced by ambient magnetic influence remarkably well,
• In other words, due to the metallic gold coating, the magnet obtains an professional appearance,
• They possess strong magnetic force measurable at the magnet’s surface,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• The ability for precise shaping and adaptation to specific needs – neodymium magnets can be manufactured in many forms and dimensions, which amplifies their functionality across industries,
• Important function in modern technologies – they are utilized in data storage devices, rotating machines, diagnostic apparatus and high-tech tools,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in tiny dimensions, which makes them useful in miniature devices

Disadvantages of magnetic elements:

• They can break when subjected to a sudden impact. If the magnets are exposed to shocks, they should be placed in a protective case. The steel housing, in the form of a holder, protects the magnet from damage and increases its overall durability,
• They lose power at extreme temperatures. Most neodymium magnets experience permanent decline in strength when heated above 80°C (depending on the form and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Magnets exposed to wet conditions can degrade. Therefore, for outdoor applications, we recommend waterproof types made of coated materials,
• Limited ability to create internal holes in the magnet – the use of a external casing is recommended,
• Possible threat related to magnet particles may arise, if ingested accidentally, which is notable in the health of young users. Moreover, minuscule fragments from these magnets have the potential to interfere with diagnostics once in the system,
• In cases of large-volume purchasing, neodymium magnet cost is a challenge,

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

The given pulling force of the magnet corresponds to the maximum force, calculated in ideal conditions, specifically:

• using a steel plate with low carbon content, serving as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a smooth surface
• with zero air gap
• with vertical force applied
• at room temperature

Lifting capacity in practice – influencing factors

Practical lifting force is dependent on elements, listed from the most critical to the less significant:

• Air gap between the magnet and the plate, as even a very small distance (e.g. 0.5 mm) causes 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 suitable thickness, under a perpendicular pulling force, whereas under attempts to slide the magnet the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet and the plate decreases the load capacity.