UMH 25x8x45 [M5] / N38 - magnetic holder with hook

Advantages as well as disadvantages of neodymium magnets.

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

• They have unchanged lifting capacity, and over more than ten years their performance decreases symbolically – ~1% (in testing),
• Neodymium magnets prove to be extremely resistant to magnetic field loss caused by magnetic disturbances,
• By applying a smooth coating of gold, the element acquires an proper look,
• Magnetic induction on the top side of the magnet remains extremely intense,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures reaching 230°C and above...
• Thanks to freedom in designing and the capacity to modify to complex applications,
• Wide application in modern industrial fields – they are used in hard drives, drive modules, medical devices, also technologically advanced constructions.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets: tips and applications.

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets suffer a drop in strength. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They oxidize in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Limited ability of making threads in the magnet and complicated forms - recommended is casing - magnet mounting.
• Health risk resulting from small fragments of magnets can be dangerous, if swallowed, which becomes key in the context of child safety. Additionally, tiny parts of these magnets can be problematic in diagnostics medical in case of swallowing.
• With large orders the cost of neodymium magnets is a challenge,

Optimal lifting capacity of a neodymium magnet – what it depends on?

The load parameter shown refers to the limit force, measured under laboratory conditions, namely:

• on a plate made of mild steel, effectively closing the magnetic field
• possessing a thickness of min. 10 mm to ensure full flux closure
• with an ground touching surface
• without the slightest insulating layer between the magnet and steel
• under perpendicular force direction (90-degree angle)
• at ambient temperature room level

What influences lifting capacity in practice

It is worth knowing that the application force will differ influenced by the following factors, in order of importance:

• Space between magnet and steel – every millimeter of separation (caused e.g. by varnish or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to pulling vertically. When attempting to slide, the magnet exhibits much less (typically approx. 20-30% of nominal force).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Plate material – mild steel gives the best results. Alloy steels decrease magnetic permeability and holding force.
• Smoothness – ideal contact is possible only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Operating temperature – NdFeB sinters have a sensitivity to temperature. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity was measured with the use of a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.