SM 25x100 [2xM8] / N42 - magnetic separator

Pros as well as cons of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They have constant strength, and over more than 10 years their attraction force decreases symbolically – ~1% (in testing),
• They retain their magnetic properties even under close interference source,
• By using a reflective coating of silver, the element presents an nice look,
• They show high magnetic induction at the operating surface, making them more effective,
• 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...
• Considering the option of free forming and customization to individualized needs, neodymium magnets can be modeled in a wide range of geometric configurations, which expands the range of possible applications,
• Versatile presence in modern technologies – they serve a role in hard drives, drive modules, advanced medical instruments, also complex engineering applications.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a strong case, which not only secures them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets suffer a drop in strength. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as 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 suggest using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
• Due to limitations in creating nuts and complicated shapes in magnets, we propose using cover - magnetic holder.
• Possible danger to health – tiny shards of magnets are risky, when accidentally swallowed, which becomes key in the context of child health protection. It is also worth noting that small components of these products are able to be problematic in diagnostics medical after entering the body.
• Due to neodymium price, their price is relatively high,

Maximum lifting force for a neodymium magnet – what contributes to it?

Information about lifting capacity was determined for the most favorable conditions, assuming:

• on a plate made of mild steel, effectively closing the magnetic flux
• possessing a thickness of at least 10 mm to avoid saturation
• characterized by lack of roughness
• under conditions of ideal adhesion (metal-to-metal)
• under perpendicular application of breakaway force (90-degree angle)
• at room temperature

Determinants of practical lifting force of a magnet

Real force is influenced by specific conditions, including (from priority):

• Clearance – existence of any layer (paint, dirt, air) interrupts the magnetic circuit, which reduces power rapidly (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is obtained only during perpendicular pulling. The shear force of the magnet along the plate is usually several times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Steel type – mild steel gives the best results. Alloy admixtures reduce magnetic properties and lifting capacity.
• Surface finish – full contact is possible only on polished steel. Rough texture reduce the real contact area, weakening the magnet.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was carried out on a smooth plate of optimal thickness, under perpendicular forces, in contrast under shearing force the holding force is lower. In addition, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.