MPL 60x10x5 / N38 - lamellar magnet

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their tremendous pulling force, neodymium magnets offer the following advantages:

• They have stable power, and over around ten years their attraction force decreases symbolically – ~1% (in testing),
• They are very resistant to demagnetization caused by external field interference,
• Thanks to the shiny finish and nickel coating, they have an aesthetic appearance,
• The outer field strength of the magnet shows advanced magnetic properties,
• Thanks to their enhanced temperature resistance, they can operate (depending on the form) even at temperatures up to 230°C or more,
• The ability for accurate shaping and customization to specific needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which enhances their versatility in applications,
• Important function in new technology industries – they are utilized in hard drives, electric motors, diagnostic apparatus and sophisticated instruments,
• Compactness – despite their small size, they provide high effectiveness, making them ideal for precision applications

Disadvantages of rare earth magnets:

• They are fragile when subjected to a powerful impact. If the magnets are exposed to physical collisions, they should be placed in a metal holder. The steel housing, in the form of a holder, protects the magnet from damage , and at the same time strengthens its overall durability,
• 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 profile). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Magnets exposed to wet conditions can corrode. Therefore, for outdoor applications, we suggest waterproof types made of non-metallic composites,
• The use of a protective casing or external holder is recommended, since machining internal cuts in neodymium magnets is risky,
• Safety concern linked to microscopic shards may arise, in case of ingestion, which is crucial in the context of child safety. Moreover, tiny components from these magnets can disrupt scanning after being swallowed,
• High unit cost – neodymium magnets are pricier than other types of magnets (e.g., ferrite), which may limit large-scale applications

Best holding force of the magnet in ideal parameters – what it depends on?

The given strength of the magnet represents the optimal strength, determined under optimal conditions, specifically:

• with the use of low-carbon steel plate acting as a magnetic yoke
• having a thickness of no less than 10 millimeters
• with a smooth surface
• with zero air gap
• in a perpendicular direction of force
• at room temperature

Lifting capacity in real conditions – factors

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

• 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 plates with a smooth surface of suitable thickness, under a perpendicular pulling force, whereas under parallel forces the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet and the plate decreases the holding force.