SM 32x425 [2xM8] / N42 - magnetic separator

Advantages as well as disadvantages of neodymium magnets.

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

• They have constant strength, and over nearly 10 years their attraction force decreases symbolically – ~1% (in testing),
• Magnets perfectly resist against demagnetization caused by foreign field sources,
• By applying a smooth layer of silver, the element acquires an elegant look,
• Magnetic induction on the working part of the magnet remains exceptional,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Due to the potential of flexible forming and adaptation to individualized projects, magnetic components can be produced in a variety of forms and dimensions, which makes them more universal,
• Universal use in modern industrial fields – they are utilized in data components, motor assemblies, precision medical tools, and modern systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, in miniature format,

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a strong case, which not only protects them against impacts but also increases their durability
• Neodymium magnets decrease 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
• They rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We suggest a housing - magnetic holder, due to difficulties in realizing threads inside the magnet and complicated shapes.
• Health risk to health – tiny shards of magnets pose a threat, if swallowed, which is particularly important in the context of child safety. It is also worth noting that small elements of these magnets are able to be problematic in diagnostics medical when they are in the body.
• Due to complex production process, their price is higher than average,

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

Holding force of 0 kg is a measurement result executed under standard conditions:

• with the application of a sheet made of special test steel, ensuring full magnetic saturation
• with a cross-section of at least 10 mm
• with a surface free of scratches
• under conditions of ideal adhesion (metal-to-metal)
• during detachment in a direction perpendicular to the mounting surface
• in temp. approx. 20°C

Lifting capacity in practice – influencing factors

Bear in mind that the application force may be lower influenced by the following factors, starting with the most relevant:

• Distance – the presence of foreign body (paint, dirt, gap) acts as an insulator, which lowers capacity steeply (even by 50% at 0.5 mm).
• Force direction – note that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Chemical composition of the base – mild steel attracts best. Alloy steels lower magnetic properties and holding force.
• Surface finish – full contact is obtained only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal factor – hot environment weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity testing was carried out on a smooth plate of suitable thickness, under perpendicular forces, in contrast under parallel forces the lifting capacity is smaller. In addition, even a slight gap {between} the magnet and the plate decreases the load capacity.