SM 19x225 [2xM6] / N50 - magnetic separator

Pros and cons of rare earth magnets.

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

• They retain full power for nearly ten years – the drop is just ~1% (in theory),
• They retain their magnetic properties even under external field action,
• The use of an shiny finish of noble metals (nickel, gold, silver) causes the element to present itself better,
• Neodymium magnets deliver maximum magnetic induction on a small area, which ensures high operational effectiveness,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to the potential of accurate shaping and adaptation to custom needs, NdFeB magnets can be modeled in a variety of shapes and sizes, which increases their versatility,
• Universal use in future technologies – they find application in magnetic memories, motor assemblies, precision medical tools, and modern systems.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Characteristics of disadvantages of neodymium magnets and proposals for their use:

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a special holder, which not only protects them against impacts but also increases their durability
• Neodymium magnets lose their force 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
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Limited possibility of producing nuts in the magnet and complex shapes - preferred is a housing - magnetic holder.
• Possible danger resulting from small fragments of magnets are risky, in case of ingestion, which is particularly important in the context of child safety. It is also worth noting that small elements of these magnets can disrupt the diagnostic process medical when they are in the body.
• With mass production the cost of neodymium magnets is a challenge,

Highest magnetic holding force – what it depends on?

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

• using a base made of low-carbon steel, serving as a magnetic yoke
• whose transverse dimension reaches at least 10 mm
• with an ground touching surface
• without the slightest clearance between the magnet and steel
• under perpendicular application of breakaway force (90-degree angle)
• in stable room temperature

Lifting capacity in real conditions – factors

Please note that the application force may be lower subject to elements below, in order of importance:

• Space between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Load vector – highest force is obtained only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – too thin plate does not accept the full field, causing part of the flux to be wasted to the other side.
• Plate material – low-carbon steel attracts best. Alloy admixtures lower magnetic properties and lifting capacity.
• Smoothness – ideal contact is obtained only on polished steel. Rough texture create air cushions, weakening the magnet.
• Temperature – temperature increase causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, however under shearing force the load capacity is reduced by as much as 5 times. Additionally, even a slight gap {between} the magnet’s surface and the plate reduces the holding force.