AM ucho [M8] - magnetic accessories

Pros as well as cons of neodymium magnets.

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

• They virtually do not lose strength, because even after 10 years the decline in efficiency is only ~1% (according to literature),
• Neodymium magnets remain highly resistant to demagnetization caused by external interference,
• In other words, due to the shiny finish of gold, the element gains visual value,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of precise modeling as well as adapting to atypical conditions,
• Universal use in high-tech industry – they serve a role in hard drives, electromotive mechanisms, medical equipment, also technologically advanced constructions.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Limited possibility of making threads in the magnet and complex shapes - preferred is casing - magnet mounting.
• Possible danger to health – tiny shards of magnets can be dangerous, in case of ingestion, which is particularly important 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.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Magnetic strength at its maximum – what contributes to it?

The lifting capacity listed is a measurement result performed under the following configuration:

• with the application of a yoke made of special test steel, guaranteeing full magnetic saturation
• whose transverse dimension reaches at least 10 mm
• characterized by lack of roughness
• under conditions of no distance (surface-to-surface)
• during detachment in a direction vertical to the mounting surface
• at temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

Real force is affected by specific conditions, mainly (from most important):

• Space between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Load vector – highest force is available only during pulling at a 90° angle. The force required to slide of the magnet along the plate is standardly many times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin sheet does not accept the full field, causing part of the power to be wasted to the other side.
• Steel type – mild steel gives the best results. Alloy steels lower magnetic permeability and holding force.
• Surface structure – the more even the plate, the better the adhesion and higher the lifting capacity. Unevenness acts like micro-gaps.
• Temperature – heating the magnet causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Holding force was tested on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under shearing force the lifting capacity is smaller. In addition, even a slight gap {between} the magnet and the plate decreases the load capacity.