UMGZ 75x34x18 [M10] GZ / N38 - magnetic holder external thread

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their magnetic capacity, neodymium magnets provide the following advantages:

• Their power remains stable, and after approximately ten years, it drops only by ~1% (according to research),
• They are highly resistant to demagnetization caused by external magnetic sources,
• Thanks to the glossy finish and silver coating, they have an visually attractive appearance,
• The outer field strength of the magnet shows remarkable magnetic properties,
• With the right combination of materials, they reach significant thermal stability, enabling operation at or above 230°C (depending on the form),
• Thanks to the possibility in shaping and the capability to adapt to individual requirements, neodymium magnets can be created in different geometries, which increases their usage potential,
• Wide application in new technology industries – they are utilized in hard drives, rotating machines, medical equipment or even sophisticated instruments,
• Compactness – despite their small size, they generate strong force, making them ideal for precision applications

Disadvantages of magnetic elements:

• They may fracture when subjected to a sudden impact. If the magnets are exposed to mechanical hits, it is suggested to place them in a metal holder. The steel housing, in the form of a holder, protects the magnet from fracture while also reinforces its overall resistance,
• They lose power at increased temperatures. Most neodymium magnets experience permanent loss in strength when heated above 80°C (depending on the geometry and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Due to corrosion risk in humid conditions, it is advisable to use sealed magnets made of rubber for outdoor use,
• Limited ability to create complex details in the magnet – the use of a mechanical support is recommended,
• Safety concern linked to microscopic shards may arise, when consumed by mistake, which is significant in the family environments. Furthermore, small elements from these devices may hinder health screening after being swallowed,
• In cases of tight budgets, neodymium magnet cost may be a barrier,

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

The given pulling force of the magnet means the maximum force, assessed in the best circumstances, specifically:

• with mild steel, serving as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a polished side
• with zero air gap
• under perpendicular detachment force
• in normal thermal conditions

Key elements affecting lifting force

In practice, the holding capacity of a magnet is affected by the following aspects, from crucial to less important:

• 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 conducted on a smooth plate of optimal thickness, under perpendicular forces, in contrast under parallel forces the holding force is lower. In addition, even a small distance {between} the magnet’s surface and the plate decreases the holding force.