MP 12x8/4x3 / N38 - ring magnet

Strengths as well as weaknesses of rare earth magnets.

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

• They retain full power for nearly ten years – the drop is just ~1% (according to analyses),
• They feature excellent resistance to magnetism drop as a result of external fields,
• By using a lustrous coating of nickel, the element gains an modern look,
• Neodymium magnets ensure maximum magnetic induction on a their surface, which allows for strong attraction,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• Thanks to the possibility of flexible shaping and adaptation to individualized projects, neodymium magnets can be created in a broad palette of shapes and sizes, which amplifies use scope,
• Versatile presence in electronics industry – they are utilized in magnetic memories, electromotive mechanisms, medical devices, and industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which allows their use in compact constructions

What to avoid - cons of neodymium magnets: tips and applications.

• 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 power (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 rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing threads and complicated forms in magnets, we propose using cover - magnetic mount.
• Potential hazard related to microscopic parts of magnets can be dangerous, if swallowed, which becomes key in the context of child health protection. Furthermore, small components of these magnets are able to complicate diagnosis medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Detachment force of the magnet in optimal conditions – what contributes to it?

Magnet power was defined for the most favorable conditions, assuming:

• on a plate made of structural steel, perfectly concentrating the magnetic flux
• whose transverse dimension is min. 10 mm
• with a plane perfectly flat
• under conditions of no distance (metal-to-metal)
• under perpendicular force direction (90-degree angle)
• at conditions approx. 20°C

Magnet lifting force in use – key factors

Effective lifting capacity is affected by specific conditions, mainly (from most important):

• Gap (betwixt the magnet and the metal), as even a very small clearance (e.g. 0.5 mm) results in a reduction in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Steel type – low-carbon steel gives the best results. Alloy admixtures decrease magnetic properties and lifting capacity.
• Smoothness – ideal contact is obtained only on smooth steel. Rough texture create air cushions, reducing force.
• Thermal environment – heating the magnet results in weakening of induction. Check the thermal limit for a given model.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, in contrast under parallel forces the load capacity is reduced by as much as 75%. Moreover, even a small distance {between} the magnet and the plate decreases the holding force.