RM R8 ULTRA - 13000 Gs / N52 - magnetic distributor

Pros and cons of neodymium magnets.

Besides their immense field intensity, neodymium magnets offer the following advantages:

• They have stable power, and over around 10 years their performance decreases symbolically – ~1% (in testing),
• They retain their magnetic properties even under strong external field,
• Thanks to the reflective finish, the coating of Ni-Cu-Ni, gold-plated, or silver-plated gives an visually attractive appearance,
• The surface of neodymium magnets generates a intense magnetic field – this is one of their assets,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Due to the possibility of precise molding and customization to specialized solutions, neodymium magnets can be modeled in a broad palette of geometric configurations, which makes them more universal,
• Wide application in future technologies – they are utilized in HDD drives, brushless drives, medical equipment, and technologically advanced constructions.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets: application proposals

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• Neodymium magnets decrease their strength 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 magnets in rubber or plastics, which prevent oxidation as well as corrosion.
• Limited possibility of creating nuts in the magnet and complex forms - preferred is cover - magnetic holder.
• Possible danger resulting from small fragments of magnets can be dangerous, in case of ingestion, which is particularly important in the context of child health protection. Additionally, small elements of these devices are able to complicate diagnosis medical when they are in the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Magnetic strength at its maximum – what affects it?

The lifting capacity listed is a result of laboratory testing executed under the following configuration:

• with the use of a sheet made of special test steel, guaranteeing maximum field concentration
• possessing a thickness of min. 10 mm to avoid saturation
• with a surface perfectly flat
• with total lack of distance (no impurities)
• during pulling in a direction vertical to the mounting surface
• at ambient temperature approx. 20 degrees Celsius

Determinants of practical lifting force of a magnet

In practice, the actual lifting capacity is determined by a number of factors, presented from most significant:

• Distance – existence of any layer (paint, dirt, air) acts as an insulator, which lowers capacity steeply (even by 50% at 0.5 mm).
• Angle of force application – maximum parameter is reached only during perpendicular pulling. The resistance to sliding of the magnet along the surface is usually many times smaller (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin plate does not accept the full field, causing part of the power to be lost into the air.
• Material composition – not every steel reacts the same. High carbon content weaken the attraction effect.
• Surface structure – the more even the plate, the larger the contact zone and stronger the hold. Unevenness creates an air distance.
• Thermal environment – heating the magnet causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity was determined using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular detachment force, in contrast under shearing force the load capacity is reduced by as much as fivefold. In addition, even a slight gap {between} the magnet and the plate lowers the lifting capacity.