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

Advantages as well as disadvantages of neodymium magnets.

Apart from their notable holding force, neodymium magnets have these key benefits:

• They have stable power, and over more than 10 years their performance decreases symbolically – ~1% (in testing),
• Neodymium magnets are characterized by extremely resistant to magnetic field loss caused by magnetic disturbances,
• Thanks to the shiny finish, the coating of Ni-Cu-Ni, gold, or silver gives an clean appearance,
• The surface of neodymium magnets generates a intense magnetic field – this is a key feature,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• In view of the ability of precise molding and customization to specialized projects, magnetic components can be created in a broad palette of shapes and sizes, which increases their versatility,
• Fundamental importance in modern technologies – they find application in data components, drive modules, medical devices, as well as modern systems.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a steel housing, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their strength 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
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in creating nuts and complex shapes in magnets, we propose using casing - magnetic mechanism.
• Possible danger related to microscopic parts of magnets pose a threat, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Additionally, small components of these magnets can disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which hinders application in large quantities

Optimal lifting capacity of a neodymium magnet – what contributes to it?

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

• with the application of a sheet made of low-carbon steel, ensuring maximum field concentration
• possessing a thickness of minimum 10 mm to ensure full flux closure
• with an ideally smooth contact surface
• without the slightest clearance between the magnet and steel
• for force acting at a right angle (in the magnet axis)
• at room temperature

Practical aspects of lifting capacity – factors

Bear in mind that the working load will differ influenced by the following factors, in order of importance:

• Distance – existence of foreign body (paint, dirt, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of converting into lifting capacity.
• Material composition – different alloys reacts the same. Alloy additives weaken the attraction effect.
• Surface quality – the smoother and more polished the plate, the better the adhesion and stronger the hold. Unevenness creates an air distance.
• Thermal environment – heating the magnet results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was assessed using a polished steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, in contrast under parallel forces the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet’s surface and the plate decreases the lifting capacity.