UMGGW 29x8 [M4] GW / N38 - magnetic holder rubber internal thread

Advantages as well as disadvantages of neodymium magnets.

Besides their immense strength, neodymium magnets offer the following advantages:

• They do not lose magnetism, even after nearly ten years – the drop in strength is only ~1% (theoretically),
• Magnets very well protect themselves against demagnetization caused by foreign field sources,
• The use of an metallic layer of noble metals (nickel, gold, silver) causes the element to look better,
• Magnets possess maximum magnetic induction on the working surface,
• Thanks to resistance to high temperature, they are capable of working (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of accurate forming and modifying to complex conditions,
• Key role in modern industrial fields – they find application in computer drives, electromotive mechanisms, diagnostic systems, also complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which enables their usage in compact constructions

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a special holder, which not only protects them against impacts but also increases their durability
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Due to limitations in producing threads and complex forms in magnets, we propose using casing - magnetic mount.
• Health risk resulting from small fragments of magnets can be dangerous, in case of ingestion, which becomes key in the aspect of protecting the youngest. Furthermore, small elements of these products are able to complicate diagnosis medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Highest magnetic holding force – what it depends on?

Holding force of 6.4 kg is a theoretical maximum value performed under the following configuration:

• using a base made of mild steel, serving as a ideal flux conductor
• whose thickness equals approx. 10 mm
• with a plane perfectly flat
• under conditions of ideal adhesion (surface-to-surface)
• for force applied at a right angle (pull-off, not shear)
• at temperature room level

Practical lifting capacity: influencing factors

In real-world applications, the real power is determined by several key aspects, listed from crucial:

• Clearance – the presence of any layer (rust, tape, air) interrupts the magnetic circuit, which reduces power rapidly (even by 50% at 0.5 mm).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Base massiveness – insufficiently thick plate does not close the flux, causing part of the flux to be escaped to the other side.
• Steel grade – ideal substrate is pure iron steel. Stainless steels may attract less.
• Smoothness – full contact is obtained only on polished steel. Any scratches and bumps create air cushions, reducing force.
• Thermal environment – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was carried out on a smooth plate of optimal thickness, under a perpendicular pulling force, however under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a slight gap {between} the magnet’s surface and the plate lowers the holding force.