UI 45x13x6 [Z323] / N38 - badge holder

Strengths and weaknesses of NdFeB magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They have stable power, and over more than ten years their performance decreases symbolically – ~1% (in testing),
• Magnets very well resist against loss of magnetization caused by ambient magnetic noise,
• A magnet with a shiny gold surface looks better,
• Magnetic induction on the working layer of the magnet turns out to be impressive,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and are able to act (depending on the form) even at a temperature of 230°C or more...
• Due to the possibility of accurate forming and adaptation to specialized requirements, neodymium magnets can be created in a broad palette of forms and dimensions, which amplifies use scope,
• Universal use in high-tech industry – they are utilized in hard drives, electric drive systems, medical devices, also modern systems.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which enables their usage in compact constructions

Characteristics of disadvantages of neodymium magnets: weaknesses and usage proposals

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only protects the magnet but also improves its resistance to damage
• Neodymium magnets lose their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• Due to limitations in producing nuts and complicated forms in magnets, we propose using a housing - magnetic holder.
• Health risk related to microscopic parts of magnets are risky, if swallowed, which gains importance in the context of child health protection. It is also worth noting that tiny parts of these products are able to be problematic in diagnostics medical in case of swallowing.
• Due to complex production process, their price is higher than average,

Best holding force of the magnet in ideal parameters – what it depends on?

The force parameter is a theoretical maximum value executed under the following configuration:

• on a base made of structural steel, effectively closing the magnetic flux
• possessing a massiveness of minimum 10 mm to ensure full flux closure
• with an polished contact surface
• under conditions of gap-free contact (metal-to-metal)
• for force acting at a right angle (pull-off, not shear)
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

During everyday use, the actual holding force is determined by a number of factors, presented from the most important:

• Clearance – the presence of any layer (paint, dirt, gap) interrupts the magnetic circuit, which reduces capacity steeply (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to detachment vertically. When attempting to slide, the magnet holds significantly lower power (often approx. 20-30% of maximum force).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of converting into lifting capacity.
• Material composition – not every steel attracts identically. High carbon content worsen the attraction effect.
• Smoothness – full contact is obtained only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal environment – heating the magnet causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was determined with the use of a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, however under parallel forces the holding force is lower. In addition, even a small distance {between} the magnet and the plate decreases the load capacity.