CM PML-3 / N45 - magnetic gripper

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They virtually do not lose strength, because even after 10 years, the performance loss is only ~1% (in laboratory conditions),
• They remain magnetized despite exposure to magnetic noise,
• Thanks to the polished finish and silver coating, they have an visually attractive appearance,
• They exhibit elevated levels of magnetic induction near the outer area of the magnet,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• With the option for customized forming and precise design, these magnets can be produced in numerous shapes and sizes, greatly improving engineering flexibility,
• Significant impact in modern technologies – they serve a purpose in computer drives, electromechanical systems, clinical machines along with other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in tiny dimensions, which makes them ideal in compact constructions

Disadvantages of NdFeB magnets:

• They are fragile when subjected to a powerful impact. If the magnets are exposed to external force, we recommend in a steel housing. The steel housing, in the form of a holder, protects the magnet from breakage and enhances its overall resistance,
• Magnets lose magnetic efficiency when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible performance loss (influenced by the magnet’s dimensions). 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 degrade. Therefore, for outdoor applications, it's best to use waterproof types made of plastic,
• Limited ability to create complex details in the magnet – the use of a housing is recommended,
• Safety concern linked to microscopic shards may arise, if ingested accidentally, which is notable in the health of young users. Furthermore, miniature parts from these devices might hinder health screening when ingested,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

Maximum lifting capacity of the magnet – what contributes to it?

The given lifting capacity of the magnet means the maximum lifting force, determined 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 refined outer layer
• with no separation
• under perpendicular detachment force
• under standard ambient temperature

What influences lifting capacity in practice

The lifting capacity of a magnet is determined by 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 assessed with the use of a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, however under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet and the plate decreases the load capacity.