MW 5x15 / N38 - cylindrical magnet

Pros as well as cons of rare earth magnets.

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

• Their power remains stable, and after approximately ten years it drops only by ~1% (according to research),
• They retain their magnetic properties even under close interference source,
• In other words, due to the aesthetic surface of silver, the element is aesthetically pleasing,
• Magnets exhibit extremely high magnetic induction on the outer layer,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Thanks to versatility in designing and the ability to modify to complex applications,
• Fundamental importance in high-tech industry – they serve a role in HDD drives, electric drive systems, medical devices, as well as other advanced devices.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

What to avoid - cons of neodymium magnets: application proposals

• To avoid cracks under impact, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (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
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Limited possibility of making threads in the magnet and complex shapes - preferred is casing - mounting mechanism.
• Possible danger resulting from small fragments of magnets can be dangerous, if swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products can be problematic in diagnostics medical after entering the body.
• Due to expensive raw materials, their price exceeds standard values,

Maximum holding power of the magnet – what affects it?

The load parameter shown represents the peak performance, recorded under ideal test conditions, namely:

• with the use of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a massiveness of min. 10 mm to avoid saturation
• with an ground touching surface
• without any air gap between the magnet and steel
• under vertical force vector (90-degree angle)
• in neutral thermal conditions

Determinants of practical lifting force of a magnet

In real-world applications, the actual lifting capacity is determined by several key aspects, listed from the most important:

• Space between magnet and steel – every millimeter of distance (caused e.g. by varnish or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to detachment vertically. When attempting to slide, the magnet exhibits significantly lower power (often approx. 20-30% of nominal force).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Material composition – not every steel reacts the same. High carbon content weaken the attraction effect.
• Surface finish – ideal contact is obtained only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. When it is hot they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was assessed using a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, however under attempts to slide the magnet the holding force is lower. Moreover, even a slight gap {between} the magnet and the plate reduces the lifting capacity.