FM Ruszt magnetyczny do leja fi 200 jednopoziomowy / N52 - magnetic filter

Pros and cons of NdFeB magnets.

Besides their immense magnetic power, neodymium magnets offer the following advantages:

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• Neodymium magnets remain extremely resistant to loss of magnetic properties caused by external interference,
• The use of an metallic layer of noble metals (nickel, gold, silver) causes the element to present itself better,
• They feature high magnetic induction at the operating surface, which improves attraction properties,
• These magnets tolerate high temperatures, often exceeding 230°C, when properly designed (in relation to form),
• Thanks to freedom in constructing and the ability to adapt to individual projects,
• Wide application in future technologies – they are utilized in mass storage devices, brushless drives, precision medical tools, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which makes them useful in compact constructions

Disadvantages of neodymium magnets:

• To avoid cracks under impact, we recommend using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
• We recommend cover - magnetic holder, due to difficulties in realizing threads inside the magnet and complex forms.
• Health risk resulting from small fragments of magnets are risky, if swallowed, which gains importance in the context of child health protection. Furthermore, small elements of these magnets are able to complicate diagnosis medical after entering 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?

The force parameter is a measurement result executed under the following configuration:

• using a base made of high-permeability steel, functioning as a magnetic yoke
• with a cross-section of at least 10 mm
• with an ideally smooth contact surface
• without any insulating layer between the magnet and steel
• during pulling in a direction vertical to the plane
• in stable room temperature

Magnet lifting force in use – key factors

It is worth knowing that the working load will differ influenced by the following factors, in order of importance:

• Gap (betwixt the magnet and the metal), since even a very small clearance (e.g. 0.5 mm) results in a decrease in lifting capacity by up to 50% (this also applies to varnish, corrosion or dirt).
• Angle of force application – highest force is reached only during perpendicular pulling. The shear force of the magnet along the surface is usually many times lower (approx. 1/5 of the lifting capacity).
• Steel thickness – too thin steel does not accept the full field, causing part of the power to be escaped into the air.
• Material composition – different alloys attracts identically. Alloy additives weaken the interaction with the magnet.
• Base smoothness – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Thermal environment – heating the magnet results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity was assessed by applying a polished steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Additionally, even a slight gap {between} the magnet’s surface and the plate lowers the load capacity.