MW 5x10 / N38 - cylindrical magnet

Pros as well as cons of neodymium magnets.

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

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• They do not lose their magnetic properties even under close interference source,
• A magnet with a metallic nickel surface has better aesthetics,
• Magnets have excellent magnetic induction on the active area,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Possibility of individual creating and optimizing to atypical requirements,
• Fundamental importance in advanced technology sectors – they are commonly used in data components, brushless drives, medical equipment, also modern systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which makes them useful in compact constructions

Disadvantages of neodymium magnets:

• At strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• NdFeB magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• Due to limitations in creating threads and complex shapes in magnets, we propose using a housing - magnetic mount.
• Health risk related to microscopic parts of magnets are risky, when accidentally swallowed, which gains importance in the context of child safety. It is also worth noting that small components of these devices can disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which hinders application in large quantities

Highest magnetic holding force – what affects it?

The force parameter is a theoretical maximum value performed under standard conditions:

• on a block made of structural steel, optimally conducting the magnetic field
• possessing a thickness of min. 10 mm to ensure full flux closure
• with a plane perfectly flat
• without the slightest clearance between the magnet and steel
• under axial force direction (90-degree angle)
• at ambient temperature room level

Determinants of practical lifting force of a magnet

In practice, the actual holding force depends on a number of factors, listed from the most important:

• 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.
• Load vector – maximum parameter is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the plate is typically many times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Metal type – different alloys reacts the same. High carbon content worsen the attraction effect.
• Surface quality – the more even the plate, the better the adhesion and stronger the hold. Roughness acts like micro-gaps.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. When it is hot they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was carried out on a smooth plate of suitable thickness, under a perpendicular pulling force, in contrast under parallel forces the load capacity is reduced by as much as 75%. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the holding force.