UMGGW 22x6 [M4] GW / N38 - magnetic holder rubber internal thread

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their immense field intensity, neodymium magnets offer the following advantages:

• They virtually do not lose strength, because even after 10 years, the performance loss is only ~1% (in laboratory conditions),
• They show exceptional resistance to demagnetization from external magnetic fields,
• The use of a decorative nickel surface provides a smooth finish,
• They possess strong magnetic force measurable at the magnet’s surface,
• Thanks to their high temperature resistance, they can operate (depending on the shape) even at temperatures up to 230°C or more,
• The ability for accurate shaping and adaptation to specific needs – neodymium magnets can be manufactured in multiple variants of geometries, which enhances their versatility in applications,
• Key role in advanced technical fields – they find application in HDDs, electric motors, medical equipment along with technologically developed systems,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in small dimensions, which makes them useful in compact constructions

Disadvantages of rare earth magnets:

• They may fracture when subjected to a strong impact. If the magnets are exposed to mechanical hits, it is advisable to use in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from cracks , and at the same time reinforces its overall resistance,
• They lose strength at extreme temperatures. Most neodymium magnets experience permanent reduction in strength when heated above 80°C (depending on the form and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Magnets exposed to humidity can oxidize. Therefore, for outdoor applications, it's best to use waterproof types made of non-metallic composites,
• Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing fine shapes directly in the magnet,
• Possible threat due to small fragments may arise, especially if swallowed, which is notable in the protection of children. Additionally, miniature parts from these magnets might complicate medical imaging if inside the body,
• In cases of tight budgets, neodymium magnet cost is a challenge,

Detachment force of the magnet in optimal conditions – what contributes to it?

The given holding capacity of the magnet corresponds to the highest holding force, calculated under optimal conditions, that is:

• with mild steel, used as a magnetic flux conductor
• of a thickness of at least 10 mm
• with a polished side
• with zero air gap
• with vertical force applied
• in normal thermal conditions

Key elements affecting lifting force

The lifting capacity of a magnet is determined by in practice the following factors, ordered from most important to least significant:

• 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 determined by applying a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, however under shearing force the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the holding force.