UMGZ 25x17x8 [M5] GZ / N38 - magnetic holder external thread

Advantages and disadvantages of neodymium magnets NdFeB.

Besides their high retention, neodymium magnets are valued for these benefits:

• They retain their attractive force for almost ten years – the drop is just ~1% (in theory),
• They show superior resistance to demagnetization from external field exposure,
• By applying a shiny layer of silver, the element gains a clean look,
• Magnetic induction on the surface of these magnets is impressively powerful,
• These magnets tolerate elevated temperatures, often exceeding 230°C, when properly designed (in relation to build),
• With the option for fine forming and precise design, these magnets can be produced in various shapes and sizes, greatly improving engineering flexibility,
• Significant impact in new technology industries – they are used in HDDs, electric motors, diagnostic apparatus along with technologically developed systems,
• Compactness – despite their small size, they generate strong force, making them ideal for precision applications

Disadvantages of rare earth magnets:

• They may fracture when subjected to a powerful impact. If the magnets are exposed to external force, they should be placed in a steel housing. The steel housing, in the form of a holder, protects the magnet from cracks while also increases its overall robustness,
• Magnets lose magnetic efficiency when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible power drop (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,
• Due to corrosion risk in humid conditions, it is recommended to use sealed magnets made of protective material for outdoor use,
• Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing threads directly in the magnet,
• Health risk related to magnet particles may arise, in case of ingestion, which is significant in the family environments. It should also be noted that tiny components from these magnets might disrupt scanning if inside the body,
• In cases of mass production, neodymium magnet cost is a challenge,

Maximum lifting force for a neodymium magnet – what affects it?

The given lifting capacity of the magnet corresponds to the maximum lifting force, determined in a perfect environment, specifically:

• with mild steel, used as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a refined outer layer
• with no separation
• with vertical force applied
• at room temperature

Determinants of lifting force in real conditions

Practical lifting force is determined by factors, by priority:

• 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 by applying a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under shearing force the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet and the plate lowers the load capacity.