AM ucho [M10] - magnetic accessories

Pros as well as cons of neodymium magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They retain magnetic properties for around 10 years – the loss is just ~1% (in theory),
• Magnets effectively protect themselves against loss of magnetization caused by ambient magnetic noise,
• The use of an refined layer of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Magnets possess extremely high magnetic induction on the surface,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling action at temperatures approaching 230°C and above...
• Thanks to flexibility in shaping and the capacity to modify to client solutions,
• Versatile presence in electronics industry – they are utilized in HDD drives, brushless drives, medical devices, as well as technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which allows their use in compact constructions

Disadvantages of neodymium magnets:

• At very strong impacts they can break, therefore we recommend placing them in strong housings. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• Limited ability of producing threads in the magnet and complicated shapes - recommended is a housing - magnet mounting.
• Potential hazard to health – tiny shards of magnets are risky, in case of ingestion, which becomes key in the context of child safety. Furthermore, small elements of these products are able to be problematic in diagnostics medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which can limit application in large quantities

Detachment force of the magnet in optimal conditions – what it depends on?

Holding force of 320 kg is a theoretical maximum value conducted under standard conditions:

• using a base made of high-permeability steel, serving as a magnetic yoke
• possessing a massiveness of minimum 10 mm to avoid saturation
• with a surface cleaned and smooth
• without the slightest clearance between the magnet and steel
• under axial force direction (90-degree angle)
• at temperature room level

Practical lifting capacity: influencing factors

Holding efficiency impacted by specific conditions, mainly (from priority):

• Distance (between the magnet and the plate), since even a microscopic distance (e.g. 0.5 mm) results in a reduction in lifting capacity by up to 50% (this also applies to paint, rust or dirt).
• Load vector – highest force is available only during perpendicular pulling. The force required to slide of the magnet along the plate is typically several times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Material composition – not every steel reacts the same. High carbon content worsen the attraction effect.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves field saturation. Rough surfaces reduce efficiency.
• 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).

* Lifting capacity was determined with the use of a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, in contrast under shearing force the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the lifting capacity.