UMH 75x18x68 [M8] / N38 - magnetic holder with hook

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• They do not lose their even during approximately ten years – the reduction of strength is only ~1% (theoretically),
• They are very resistant to demagnetization caused by external magnetic sources,
• Thanks to the glossy finish and nickel coating, they have an aesthetic appearance,
• They have extremely strong magnetic induction on the surface of the magnet,
• These magnets tolerate extreme temperatures, often exceeding 230°C, when properly designed (in relation to build),
• With the option for tailored forming and personalized design, these magnets can be produced in numerous shapes and sizes, greatly improving application potential,
• Wide application in new technology industries – they are used in data storage devices, electromechanical systems, healthcare devices or even other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer intense magnetic field in small dimensions, which makes them useful in miniature devices

Disadvantages of rare earth magnets:

• They are prone to breaking when subjected to a heavy impact. If the magnets are exposed to mechanical hits, we recommend in a protective case. The steel housing, in the form of a holder, protects the magnet from cracks and increases its overall resistance,
• 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 form). 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 wise to use sealed magnets made of protective material for outdoor use,
• Using a cover – such as a magnetic holder – is advised due to the restrictions in manufacturing complex structures directly in the magnet,
• Potential hazard related to magnet particles may arise, if ingested accidentally, which is crucial in the health of young users. Additionally, minuscule fragments from these devices might disrupt scanning if inside the body,
• Due to a complex production process, their cost is above average,

Maximum holding power of the magnet – what contributes to it?

The given pulling force of the magnet means the maximum force, determined in a perfect environment, 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
• under perpendicular detachment force
• under standard ambient temperature

What influences lifting capacity in practice

Practical lifting force is determined by elements, by priority:

• Air gap between the magnet and the plate, as 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 testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under parallel forces the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet’s surface and the plate reduces the load capacity.