HH 42x8.8 [M6] / N38 - through hole magnetic holder

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They have stable power, and over more than ten years their attraction force decreases symbolically – ~1% (in testing),
• They remain magnetized despite exposure to magnetic surroundings,
• By applying a bright layer of silver, the element gains a sleek look,
• They have exceptional magnetic induction on the surface of the magnet,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• The ability for accurate shaping and customization to individual needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which amplifies their functionality across industries,
• Key role in cutting-edge sectors – they are utilized in hard drives, electromechanical systems, diagnostic apparatus along with technologically developed systems,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of magnetic elements:

• They may fracture when subjected to a heavy impact. If the magnets are exposed to physical collisions, it is advisable to use in a steel housing. The steel housing, in the form of a holder, protects the magnet from breakage while also increases its overall strength,
• High temperatures may significantly reduce the field efficiency of neodymium magnets. Typically, above 80°C, they experience permanent loss in performance (depending on height). To prevent this, we offer heat-resistant magnets marked [AH], capable of working up to 230°C, which makes them perfect for high-temperature use,
• Magnets exposed to humidity can rust. Therefore, for outdoor applications, we suggest waterproof types made of plastic,
• The use of a protective casing or external holder is recommended, since machining multi-axis shapes in neodymium magnets is not feasible,
• Potential hazard related to magnet particles may arise, when consumed by mistake, which is important in the context of child safety. Moreover, tiny components from these products can complicate medical imaging once in the system,
• Due to expensive raw materials, their cost is relatively high,

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

The given holding capacity of the magnet corresponds to the highest holding force, determined under optimal conditions, namely:

• with mild steel, serving as a magnetic flux conductor
• with a thickness of minimum 10 mm
• with a polished side
• with zero air gap
• in a perpendicular direction of force
• under standard ambient temperature

Lifting capacity in real conditions – factors

In practice, the holding capacity of a magnet is conditioned by the following aspects, in descending order of importance:

• 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.

* Lifting capacity was measured using a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under parallel forces the holding force is lower. Moreover, even a minimal clearance {between} the magnet’s surface and the plate lowers the load capacity.