MPL 30x10x5 / N38 - lamellar magnet

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their immense strength, neodymium magnets offer the following advantages:

• They virtually do not lose strength, because even after ten years, the decline in efficiency is only ~1% (in laboratory conditions),
• They are highly resistant to demagnetization caused by external magnetic sources,
• Thanks to the glossy finish and gold coating, they have an elegant appearance,
• They exhibit elevated levels of magnetic induction near the outer area of the magnet,
• Neodymium magnets are known for strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the geometry),
• The ability for precise shaping and adaptation to custom needs – neodymium magnets can be manufactured in many forms and dimensions, which extends the scope of their use cases,
• Important function in advanced technical fields – they find application in data storage devices, electric motors, healthcare devices or even technologically developed systems,
• Relatively small size with high magnetic force – neodymium magnets offer intense magnetic field in compact dimensions, which makes them ideal in miniature devices

Disadvantages of magnetic elements:

• They are fragile when subjected to a powerful impact. If the magnets are exposed to external force, they should be placed in a protective case. The steel housing, in the form of a holder, protects the magnet from damage while also reinforces its overall strength,
• Magnets lose magnetic efficiency 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,
• They rust in a wet environment. For outdoor use, we recommend using sealed magnets, such as those made of rubber,
• The use of a protective casing or external holder is recommended, since machining internal cuts in neodymium magnets is difficult,
• Health risk from tiny pieces may arise, if ingested accidentally, which is important in the health of young users. Additionally, miniature parts from these devices can complicate medical imaging once in the system,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

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

The given strength of the magnet means the optimal strength, assessed in ideal conditions, namely:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a smooth surface
• with zero air gap
• under perpendicular detachment force
• under standard ambient temperature

Practical lifting capacity: influencing factors

The lifting capacity of a magnet depends on in practice the following factors, from primary to secondary:

• Air gap between the magnet and the plate, because 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 was determined using a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under parallel forces the holding force is lower. Additionally, even a slight gap {between} the magnet’s surface and the plate lowers the load capacity.