MPL 30x10x5 / N38 - lamellar magnet

Advantages and disadvantages of neodymium magnets NdFeB.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They virtually do not lose power, because even after ten years, the performance loss is only ~1% (according to literature),
• They protect against demagnetization induced by external magnetic influence very well,
• The use of a polished nickel surface provides a refined finish,
• They possess strong magnetic force measurable at the magnet’s surface,
• These magnets tolerate elevated temperatures, often exceeding 230°C, when properly designed (in relation to form),
• With the option for customized forming and personalized design, these magnets can be produced in multiple shapes and sizes, greatly improving engineering flexibility,
• Important function in modern technologies – they find application in hard drives, electromechanical systems, medical equipment along with high-tech tools,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in compact dimensions, which allows for use in small systems

Disadvantages of NdFeB magnets:

• They may fracture when subjected to a sudden impact. If the magnets are exposed to mechanical hits, it is advisable to use in a steel housing. The steel housing, in the form of a holder, protects the magnet from cracks , and at the same time reinforces its overall resistance,
• Magnets lose field strength when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible magnetic decay (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 wise to use sealed magnets made of protective material for outdoor use,
• Limited ability to create precision features in the magnet – the use of a external casing is recommended,
• Safety concern due to small fragments may arise, especially if swallowed, which is important in the context of child safety. It should also be noted that minuscule fragments from these magnets can disrupt scanning if inside the body,
• In cases of tight budgets, neodymium magnet cost is a challenge,

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

The given strength of the magnet means the optimal strength, measured in ideal conditions, specifically:

• 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
• in conditions of no clearance
• under perpendicular detachment force
• under standard ambient temperature

Key elements affecting lifting force

In practice, the holding capacity of a magnet is conditioned by these factors, arranged from the most important to the least relevant:

• Air gap between the magnet and the plate, because 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.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate decreases the lifting capacity.