SM 32x375 [2xM8] / N42 - magnetic separator

Advantages and disadvantages of rare earth magnets.

Besides their tremendous field intensity, neodymium magnets offer the following advantages:

• They do not lose strength, even during approximately ten years – the drop in lifting capacity is only ~1% (according to tests),
• Neodymium magnets are characterized by highly resistant to magnetic field loss caused by magnetic disturbances,
• By applying a decorative coating of silver, the element acquires an modern look,
• Magnetic induction on the working part of the magnet is very high,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to freedom in designing and the ability to adapt to individual projects,
• Wide application in future technologies – they are used in mass storage devices, electric drive systems, diagnostic systems, and 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 fracture. We advise keeping them in a strong case, which not only protects them against impacts but also raises their durability
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Limited ability of producing nuts in the magnet and complex shapes - preferred is cover - mounting mechanism.
• Potential hazard resulting from small fragments of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child safety. It is also worth noting that small components of these products can disrupt the diagnostic process medical when they are in the body.
• Due to complex production process, their price exceeds standard values,

Optimal lifting capacity of a neodymium magnet – what affects it?

The specified lifting capacity concerns the peak performance, recorded under laboratory conditions, specifically:

• using a base made of low-carbon steel, acting as a ideal flux conductor
• whose transverse dimension is min. 10 mm
• with an polished touching surface
• under conditions of no distance (surface-to-surface)
• under perpendicular application of breakaway force (90-degree angle)
• at standard ambient temperature

Determinants of practical lifting force of a magnet

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

• Clearance – the presence of any layer (paint, tape, gap) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to detachment vertically. When attempting to slide, the magnet holds much less (typically approx. 20-30% of maximum force).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Chemical composition of the base – low-carbon steel attracts best. Alloy admixtures decrease magnetic permeability and lifting capacity.
• Surface structure – the more even the plate, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Temperature influence – high temperature reduces pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was determined using a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under shearing force the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet and the plate decreases the load capacity.