MW 14x10 / N38 - cylindrical magnet

Pros and cons of NdFeB magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They have stable power, and over nearly ten years their performance decreases symbolically – ~1% (according to theory),
• They possess excellent resistance to magnetism drop when exposed to external fields,
• A magnet with a metallic silver surface looks better,
• Neodymium magnets generate maximum magnetic induction on a small surface, which ensures high operational effectiveness,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• Possibility of exact modeling as well as optimizing to complex requirements,
• Key role in high-tech industry – they serve a role in data components, electromotive mechanisms, diagnostic systems, as well as other advanced devices.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Problematic aspects of neodymium magnets: application proposals

• Brittleness is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a steel housing, which not only secures them against impacts but also raises their durability
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop 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 extremely 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 producing threads and complex shapes in magnets, we propose using a housing - magnetic mount.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Additionally, small elements of these magnets are able to be problematic in diagnostics medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which can limit application in large quantities

Maximum lifting capacity of the magnet – what it depends on?

The specified lifting capacity represents the peak performance, recorded under ideal test conditions, specifically:

• with the use of a sheet made of low-carbon steel, ensuring maximum field concentration
• whose transverse dimension is min. 10 mm
• characterized by lack of roughness
• under conditions of gap-free contact (surface-to-surface)
• during pulling in a direction perpendicular to the mounting surface
• at temperature room level

Determinants of lifting force in real conditions

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

• Gap between magnet and steel – every millimeter of distance (caused e.g. by veneer or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet holds significantly lower power (typically approx. 20-30% of nominal force).
• Base massiveness – insufficiently thick plate causes magnetic saturation, causing part of the power to be escaped to the other side.
• Steel grade – the best choice is pure iron steel. Hardened steels may have worse magnetic properties.
• Surface structure – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Thermal factor – hot environment reduces magnetic field. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was performed on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, whereas under shearing force the load capacity is reduced by as much as 75%. In addition, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.