AM lina fi 10 mm - magnetic accessories

Pros and cons of neodymium magnets.

Besides their exceptional strength, neodymium magnets offer the following advantages:

• They retain attractive force for almost 10 years – the drop is just ~1% (according to analyses),
• They are resistant to demagnetization induced by external field influence,
• The use of an refined layer of noble metals (nickel, gold, silver) causes the element to look better,
• The surface of neodymium magnets generates a intense magnetic field – this is one of their assets,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures approaching 230°C and above...
• Thanks to modularity in shaping and the ability to modify to client solutions,
• Huge importance in modern industrial fields – they serve a role in hard drives, electric motors, diagnostic systems, also complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which allows their use in miniature devices

Drawbacks and weaknesses of neodymium magnets and ways of using them

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets decrease their force 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 usually rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation and corrosion.
• We recommend cover - magnetic mount, due to difficulties in creating nuts inside the magnet and complicated forms.
• Possible danger to health – tiny shards of magnets are risky, when accidentally swallowed, which gains importance in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products can disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum holding power of the magnet – what contributes to it?

The force parameter is a result of laboratory testing executed under standard conditions:

• using a sheet made of mild steel, acting as a circuit closing element
• whose thickness is min. 10 mm
• with a surface perfectly flat
• without any insulating layer between the magnet and steel
• during detachment in a direction vertical to the mounting surface
• at room temperature

Practical lifting capacity: influencing factors

It is worth knowing that the application force may be lower subject to the following factors, in order of importance:

• Clearance – the presence of foreign body (paint, tape, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Angle of force application – maximum parameter is reached only during pulling at a 90° angle. The force required to slide of the magnet along the surface is usually several times smaller (approx. 1/5 of the lifting capacity).
• Wall thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Steel type – low-carbon steel attracts best. Alloy admixtures decrease magnetic properties and lifting capacity.
• Surface finish – ideal contact is obtained only on polished steel. Rough texture reduce the real contact area, reducing force.
• Operating temperature – NdFeB sinters have a sensitivity to temperature. At higher temperatures they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was conducted on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet’s surface and the plate decreases the lifting capacity.