ZM XMAG2 210 elementów - magnetic toy

Advantages and disadvantages of neodymium magnets NdFeB.

Apart from their notable holding force, neodymium magnets have these key benefits:

• Their magnetic field remains stable, and after around 10 years, it drops only by ~1% (according to research),
• They show exceptional resistance to demagnetization from external magnetic fields,
• By applying a shiny layer of nickel, the element gains a modern look,
• They exhibit superior levels of magnetic induction near the outer area of the magnet,
• Neodymium magnets are known for strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the magnetic form),
• The ability for accurate shaping as well as adaptation to custom needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which extends the scope of their use cases,
• Significant impact in advanced technical fields – they find application in computer drives, electric drives, diagnostic apparatus and other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer intense magnetic field in compact dimensions, which makes them ideal in small systems

Disadvantages of NdFeB magnets:

• They are prone to breaking when subjected to a powerful impact. If the magnets are exposed to mechanical hits, it is suggested to place them in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage while also reinforces its overall durability,
• Magnets lose power when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible magnetic decay (influenced by the magnet’s form). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• They rust in a humid environment. For outdoor use, we recommend using moisture-resistant magnets, such as those made of plastic,
• Limited ability to create threads in the magnet – the use of a housing is recommended,
• Possible threat related to magnet particles may arise, when consumed by mistake, which is important in the context of child safety. Moreover, small elements from these magnets might hinder health screening after being swallowed,
• Due to the price of neodymium, their cost is above average,

Optimal lifting capacity of a neodymium magnet – what affects it?

The given strength of the magnet means the optimal strength, assessed in ideal conditions, that is:

• with the use of low-carbon steel plate acting as a magnetic yoke
• having a thickness of no less than 10 millimeters
• with a refined outer layer
• with no separation
• with vertical force applied
• under standard ambient temperature

Magnet lifting force in use – key factors

The lifting capacity of a magnet depends on in practice key elements, according to their importance:

• Air gap between the magnet and the plate, because 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 was determined with the use of a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under parallel forces the holding force is lower. In addition, even a minimal clearance {between} the magnet’s surface and the plate lowers the lifting capacity.