SM 32x225 [2xM8] / N52 - magnetic separator

Pros as well as cons of rare earth magnets.

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

• They do not lose power, even during around 10 years – the reduction in power is only ~1% (theoretically),
• They possess excellent resistance to magnetism drop as a result of external fields,
• By applying a decorative layer of nickel, the element has an modern look,
• They are known for high magnetic induction at the operating surface, which increases their power,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling functioning at temperatures approaching 230°C and above...
• Thanks to freedom in designing and the ability to customize to individual projects,
• Key role in future technologies – they are commonly used in magnetic memories, electric motors, advanced medical instruments, and technologically advanced constructions.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• We warn that neodymium magnets can lose their power 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 advise using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• We recommend a housing - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complicated shapes.
• Health risk related to microscopic parts of magnets are risky, if swallowed, which gains importance in the aspect of protecting the youngest. Furthermore, small elements of these magnets can complicate diagnosis medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum lifting capacity of the magnet – what it depends on?

The declared magnet strength represents the limit force, measured under laboratory conditions, specifically:

• using a sheet made of high-permeability steel, serving as a circuit closing element
• whose thickness equals approx. 10 mm
• characterized by smoothness
• under conditions of no distance (metal-to-metal)
• under axial force direction (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

Impact of factors on magnetic holding capacity in practice

Please note that the working load may be lower influenced by elements below, starting with the most relevant:

• Distance – the presence of any layer (rust, tape, gap) acts as an insulator, which lowers power rapidly (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is available only during pulling at a 90° angle. The shear force of the magnet along the plate is typically many times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – insufficiently thick steel causes magnetic saturation, causing part of the power to be wasted to the other side.
• Material composition – not every steel reacts the same. Alloy additives weaken the interaction with the magnet.
• Base smoothness – the more even the surface, the larger the contact zone and stronger the hold. Unevenness creates an air distance.
• Temperature influence – hot environment weakens magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was performed on a smooth plate of suitable thickness, under a perpendicular pulling force, whereas under attempts to slide the magnet the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate reduces the lifting capacity.