MW 5x15 / N38 - cylindrical magnet

Strengths as well as weaknesses of NdFeB magnets.

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

• They retain attractive force for nearly ten years – the loss is just ~1% (in theory),
• Magnets effectively protect themselves against demagnetization caused by external fields,
• Thanks to the elegant finish, the coating of nickel, gold-plated, or silver-plated gives an professional appearance,
• Neodymium magnets generate maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
• Thanks to freedom in forming and the capacity to adapt to specific needs,
• Fundamental importance in electronics industry – they find application in computer drives, electric drive systems, diagnostic systems, also other advanced devices.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Cons of neodymium magnets: weaknesses and usage proposals

• At strong impacts they can break, therefore we advise placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's 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 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 resistant to moisture, when using outdoors
• Due to limitations in creating threads and complex shapes in magnets, we recommend using cover - magnetic holder.
• Potential hazard to health – tiny shards of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child safety. Furthermore, tiny parts of these magnets can complicate diagnosis medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum holding power of the magnet – what affects it?

Breakaway force was determined for ideal contact conditions, including:

• on a base made of mild steel, optimally conducting the magnetic field
• with a cross-section of at least 10 mm
• characterized by smoothness
• with direct contact (without coatings)
• under axial force direction (90-degree angle)
• in stable room temperature

Practical aspects of lifting capacity – factors

During everyday use, the actual holding force results from a number of factors, presented from the most important:

• Clearance – the presence of any layer (rust, tape, air) acts as an insulator, which lowers power steeply (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet exhibits much less (often approx. 20-30% of nominal force).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Metal type – not every steel reacts the same. Alloy additives worsen the attraction effect.
• Smoothness – ideal contact is possible only on smooth steel. Rough texture create air cushions, weakening the magnet.
• Temperature – heating the magnet results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under parallel forces the lifting capacity is smaller. In addition, even a small distance {between} the magnet and the plate reduces the lifting capacity.