UMH 20x7x35 [M4] / N38 - magnetic holder with hook

Advantages as well as disadvantages of neodymium magnets.

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

• They retain full power for almost 10 years – the loss is just ~1% (according to analyses),
• They possess excellent resistance to magnetic field loss as a result of opposing magnetic fields,
• A magnet with a metallic silver surface looks better,
• The surface of neodymium magnets generates a concentrated magnetic field – this is a key feature,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to versatility in designing and the ability to adapt to client solutions,
• Universal use in advanced technology sectors – they are used in hard drives, motor assemblies, precision medical tools, as well as complex engineering applications.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

What to avoid - cons of neodymium magnets and ways of using them

• To avoid cracks under impact, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop 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
• They oxidize in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in creating threads and complicated forms in magnets, we propose using casing - magnetic mount.
• Potential hazard resulting from small fragments of magnets pose a threat, when accidentally swallowed, which gains importance in the context of child health protection. It is also worth noting that tiny parts of these products can complicate diagnosis medical in case of swallowing.
• With budget limitations the cost of neodymium magnets is economically unviable,

Magnetic strength at its maximum – what contributes to it?

Information about lifting capacity was determined for optimal configuration, including:

• using a plate made of high-permeability steel, acting as a circuit closing element
• whose thickness is min. 10 mm
• with an polished touching surface
• under conditions of gap-free contact (metal-to-metal)
• for force acting at a right angle (in the magnet axis)
• in temp. approx. 20°C

Practical aspects of lifting capacity – factors

In real-world applications, the actual holding force results from many variables, ranked from most significant:

• Space between surfaces – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) diminishes the pulling force, often by half at just 0.5 mm.
• Force direction – note that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Steel thickness – too thin plate does not close the flux, causing part of the power to be wasted into the air.
• Material type – the best choice is high-permeability steel. Cast iron may generate lower lifting capacity.
• Base smoothness – the more even the plate, the better the adhesion and higher the lifting capacity. Unevenness acts like micro-gaps.
• Temperature influence – hot environment reduces magnetic field. Too high temperature can permanently damage the magnet.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under attempts to slide the magnet the load capacity is reduced by as much as 5 times. In addition, even a minimal clearance {between} the magnet and the plate reduces the load capacity.