NCM 30x13.5x5 / N38 - channel magnetic holder

Strengths and weaknesses of NdFeB magnets.

Besides their remarkable pulling force, neodymium magnets offer the following advantages:

• They retain magnetic properties for almost 10 years – the loss is just ~1% (based on simulations),
• They have excellent resistance to magnetism drop due to opposing magnetic fields,
• By using a shiny layer of gold, the element gains an nice look,
• Magnetic induction on the top side of the magnet remains maximum,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• In view of the potential of precise molding and customization to unique solutions, NdFeB magnets can be manufactured in a wide range of shapes and sizes, which increases their versatility,
• Universal use in high-tech industry – they find application in data components, electric motors, medical equipment, as well as multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which allows their use in small systems

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can break. We recommend keeping them in a special holder, which not only secures them against impacts but also increases their durability
• Neodymium magnets lose power 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 very resistant to heat
• They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We suggest casing - magnetic mechanism, due to difficulties in creating threads inside the magnet and complex shapes.
• Potential hazard resulting from small fragments of magnets are risky, if swallowed, which gains importance in the context of child safety. Additionally, tiny parts of these magnets can complicate diagnosis medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Breakaway strength of the magnet in ideal conditions – what it depends on?

Breakaway force was determined for optimal configuration, taking into account:

• on a plate made of mild steel, effectively closing the magnetic field
• possessing a thickness of min. 10 mm to avoid saturation
• with a plane perfectly flat
• under conditions of no distance (surface-to-surface)
• during detachment in a direction perpendicular to the mounting surface
• at ambient temperature room level

Magnet lifting force in use – key factors

Holding efficiency is affected by working environment parameters, mainly (from most important):

• Clearance – existence of foreign body (rust, tape, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Direction of force – highest force is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is standardly many times lower (approx. 1/5 of the lifting capacity).
• Base massiveness – insufficiently thick plate does not accept the full field, causing part of the flux to be wasted into the air.
• Chemical composition of the base – low-carbon steel attracts best. Higher carbon content decrease magnetic properties and lifting capacity.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves force. Rough surfaces weaken the grip.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Holding force was checked on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate lowers the holding force.