MW 6x2 / N38 - cylindrical magnet

Strengths as well as weaknesses of neodymium magnets.

Apart from their consistent power, neodymium magnets have these key benefits:

• They retain attractive force for nearly 10 years – the drop is just ~1% (according to analyses),
• Magnets effectively resist against demagnetization caused by foreign field sources,
• A magnet with a smooth silver surface has better aesthetics,
• They show high magnetic induction at the operating surface, making them more effective,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of accurate creating as well as optimizing to specific requirements,
• Significant place in innovative solutions – they serve a role in mass storage devices, electric drive systems, advanced medical instruments, also other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which makes them useful in miniature devices

Cons of neodymium magnets and proposals for their use:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in realizing threads and complex shapes in magnets, we recommend using cover - magnetic mechanism.
• Health risk resulting from small fragments of magnets are risky, if swallowed, which is particularly important in the context of child health protection. Furthermore, small elements of these products are able to be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Magnetic strength at its maximum – what contributes to it?

The specified lifting capacity refers to the maximum value, recorded under ideal test conditions, namely:

• using a base made of mild steel, functioning as a magnetic yoke
• whose thickness equals approx. 10 mm
• with a plane cleaned and smooth
• without the slightest air gap between the magnet and steel
• during detachment in a direction vertical to the plane
• at temperature room level

Lifting capacity in practice – influencing factors

During everyday use, the actual lifting capacity results from a number of factors, listed from most significant:

• Air gap (between the magnet and the metal), because even a tiny distance (e.g. 0.5 mm) results in a drastic drop in force by up to 50% (this also applies to varnish, rust or dirt).
• Force direction – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Material composition – not every steel reacts the same. High carbon content worsen the attraction effect.
• Surface condition – ground elements guarantee perfect abutment, which increases force. Rough surfaces reduce efficiency.
• Thermal factor – hot environment weakens pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was measured by applying a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, however under attempts to slide the magnet the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate decreases the load capacity.