MP 5x2.7/1.2x5 C / N38 - ring magnet

Pros and cons of neodymium magnets.

Besides their immense magnetic power, neodymium magnets offer the following advantages:

• They do not lose strength, even after approximately 10 years – the drop in power is only ~1% (based on measurements),
• They are extremely resistant to demagnetization induced by presence of other magnetic fields,
• Thanks to the shimmering finish, the layer of nickel, gold-plated, or silver-plated gives an aesthetic appearance,
• Magnetic induction on the working layer of the magnet remains strong,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling functioning at temperatures reaching 230°C and above...
• Thanks to freedom in forming and the ability to adapt to complex applications,
• Huge importance in high-tech industry – they serve a role in data components, electric drive systems, diagnostic systems, as well as multitasking production systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of neodymium magnets:

• To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (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 very resistant to heat
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture, in case of application outdoors
• Due to limitations in creating nuts and complicated forms in magnets, we propose using cover - magnetic mount.
• Potential hazard resulting from small fragments of magnets are risky, if swallowed, which becomes key in the aspect of protecting the youngest. Additionally, small components of these magnets can disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

Holding force of 0.56 kg is a result of laboratory testing executed under standard conditions:

• on a block made of structural steel, perfectly concentrating the magnetic field
• with a thickness no less than 10 mm
• with a plane perfectly flat
• without any clearance between the magnet and steel
• during pulling in a direction perpendicular to the mounting surface
• at standard ambient temperature

Lifting capacity in real conditions – factors

Holding efficiency is influenced by specific conditions, mainly (from priority):

• Clearance – existence of foreign body (paint, dirt, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Force direction – note that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Plate thickness – too thin plate does not accept the full field, causing part of the flux to be wasted into the air.
• Metal type – not every steel reacts the same. High carbon content weaken the attraction effect.
• Smoothness – full contact is obtained only on smooth steel. Any scratches and bumps create air cushions, weakening the magnet.
• Thermal factor – high temperature weakens pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under parallel forces the load capacity is reduced by as much as 75%. Additionally, even a slight gap {between} the magnet’s surface and the plate decreases the load capacity.