SM 25x225 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of neodymium magnets.

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

• They have stable power, and over nearly ten years their attraction force decreases symbolically – ~1% (in testing),
• They are noted for resistance to demagnetization induced by external field influence,
• In other words, due to the aesthetic finish of gold, the element gains visual value,
• Magnets are distinguished by impressive magnetic induction on the outer layer,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Thanks to the option of flexible forming and customization to individualized requirements, NdFeB magnets can be created in a variety of geometric configurations, which expands the range of possible applications,
• Universal use in modern technologies – they are utilized in data components, brushless drives, medical devices, as well as complex engineering applications.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Problematic aspects of neodymium magnets and ways of using them

• To avoid cracks under impact, we suggest using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets experience a drop in strength. 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
• We recommend cover - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complex shapes.
• Possible danger resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which is particularly important in the aspect of protecting the youngest. Additionally, small elements of these magnets are able to disrupt the diagnostic process medical when they are in the body.
• With large orders the cost of neodymium magnets is economically unviable,

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

The lifting capacity listed is a measurement result executed under specific, ideal conditions:

• using a plate made of high-permeability steel, serving as a ideal flux conductor
• with a thickness no less than 10 mm
• characterized by even structure
• under conditions of gap-free contact (metal-to-metal)
• during detachment in a direction perpendicular to the plane
• at temperature approx. 20 degrees Celsius

Impact of factors on magnetic holding capacity in practice

Bear in mind that the working load will differ influenced by elements below, starting with the most relevant:

• Distance – existence of any layer (rust, tape, gap) acts as an insulator, which reduces power rapidly (even by 50% at 0.5 mm).
• Force direction – remember that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Chemical composition of the base – mild steel attracts best. Higher carbon content decrease magnetic properties and holding force.
• Plate texture – smooth surfaces ensure maximum contact, which improves force. Uneven metal weaken the grip.
• Temperature – heating the magnet causes a temporary drop of induction. Check the maximum operating temperature for a given model.

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