MPL 3x3x1 / N38 - lamellar magnet

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• They have unchanged lifting capacity, and over around 10 years their performance decreases symbolically – ~1% (according to theory),
• They remain magnetized despite exposure to magnetic noise,
• In other words, due to the shiny silver coating, the magnet obtains an professional appearance,
• They have exceptional magnetic induction on the surface of the magnet,
• With the right combination of magnetic alloys, they reach increased thermal stability, enabling operation at or above 230°C (depending on the structure),
• The ability for custom shaping or adaptation to custom needs – neodymium magnets can be manufactured in many forms and dimensions, which amplifies their functionality across industries,
• Wide application in advanced technical fields – they serve a purpose in computer drives, electric drives, medical equipment or even sophisticated instruments,
• Relatively small size with high magnetic force – neodymium magnets offer intense magnetic field in small dimensions, which allows for use in small systems

Disadvantages of magnetic elements:

• They can break when subjected to a heavy impact. If the magnets are exposed to external force, they should be placed in a metal holder. The steel housing, in the form of a holder, protects the magnet from cracks and reinforces its overall durability,
• Magnets lose field strength when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (influenced by the magnet’s structure). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Due to corrosion risk in humid conditions, it is recommended to use sealed magnets made of plastic for outdoor use,
• Limited ability to create threads in the magnet – the use of a mechanical support is recommended,
• Health risk from tiny pieces may arise, in case of ingestion, which is important in the family environments. Moreover, miniature parts from these devices may disrupt scanning when ingested,
• In cases of mass production, neodymium magnet cost may be a barrier,

Maximum magnetic pulling force – what affects it?

The given pulling force of the magnet means the maximum force, measured in a perfect environment, namely:

• with the use of low-carbon steel plate serving as a magnetic yoke
• of a thickness of at least 10 mm
• with a refined outer layer
• with zero air gap
• with vertical force applied
• at room temperature

Practical lifting capacity: influencing factors

Practical lifting force is dependent on elements, by priority:

• Air gap between the magnet and the plate, since 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 a smooth plate of suitable thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the holding force is lower. Additionally, even a minimal clearance {between} the magnet and the plate lowers the load capacity.