SM 25x325 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of neodymium magnets.

In addition to their magnetic capacity, neodymium magnets provide the following advantages:

• They have constant strength, and over around ten years their attraction force decreases symbolically – ~1% (according to theory),
• They do not lose their magnetic properties even under strong external field,
• A magnet with a smooth gold surface has better aesthetics,
• The surface of neodymium magnets generates a unique magnetic field – this is one of their assets,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures reaching 230°C and above...
• Thanks to modularity in constructing and the capacity to modify to unusual requirements,
• Versatile presence in modern technologies – they serve a role in mass storage devices, electric motors, advanced medical instruments, as well as complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which allows their use in compact constructions

Cons of neodymium magnets: tips and applications.

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Limited possibility of producing nuts in the magnet and complicated shapes - recommended is cover - mounting mechanism.
• Possible danger resulting from small fragments of magnets can be dangerous, if swallowed, which becomes key in the context of child safety. It is also worth noting that tiny parts of these devices are able to complicate diagnosis medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which can limit application in large quantities

Breakaway strength of the magnet in ideal conditions – what affects it?

Breakaway force was defined for optimal configuration, assuming:

• on a plate made of structural steel, optimally conducting the magnetic flux
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with a surface free of scratches
• with direct contact (no impurities)
• under axial force vector (90-degree angle)
• in temp. approx. 20°C

Magnet lifting force in use – key factors

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

• Air gap (between the magnet and the metal), because even a very small clearance (e.g. 0.5 mm) leads to a reduction in force by up to 50% (this also applies to varnish, rust or dirt).
• Force direction – catalog parameter refers to detachment vertically. When slipping, the magnet holds significantly lower power (often approx. 20-30% of maximum force).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Steel grade – ideal substrate is high-permeability steel. Stainless steels may attract less.
• Plate texture – smooth surfaces guarantee perfect abutment, which increases field saturation. Uneven metal weaken the grip.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. When it is hot they lose power, and in frost gain strength (up to a certain limit).

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under parallel forces the holding force is lower. Additionally, even a slight gap {between} the magnet’s surface and the plate lowers the holding force.