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

Strengths as well as weaknesses of neodymium magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (in laboratory conditions),
• They show high resistance to demagnetization induced by presence of other magnetic fields,
• A magnet with a metallic nickel surface looks better,
• They show high magnetic induction at the operating surface, which affects their effectiveness,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, allowing for functioning at temperatures approaching 230°C and above...
• Possibility of detailed forming and adjusting to individual conditions,
• Versatile presence in modern industrial fields – they serve a role in mass storage devices, drive modules, diagnostic systems, and other advanced devices.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Disadvantages of NdFeB magnets:

• To avoid cracks under impact, we suggest using special steel holders. Such a solution protects the magnet and simultaneously improves its durability.
• NdFeB magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• They oxidize in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We suggest a housing - magnetic mount, due to difficulties in realizing threads inside the magnet and complex shapes.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products can disrupt the diagnostic process medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Magnetic strength at its maximum – what contributes to it?

The lifting capacity listed is a result of laboratory testing performed under the following configuration:

• with the application of a yoke made of low-carbon steel, ensuring full magnetic saturation
• possessing a thickness of at least 10 mm to avoid saturation
• characterized by even structure
• under conditions of ideal adhesion (metal-to-metal)
• under perpendicular application of breakaway force (90-degree angle)
• at ambient temperature room level

Lifting capacity in real conditions – factors

It is worth knowing that the application force will differ influenced by the following factors, starting with the most relevant:

• Clearance – the presence of any layer (paint, tape, gap) acts as an insulator, which lowers power steeply (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet holds much less (often approx. 20-30% of nominal force).
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Material composition – different alloys reacts the same. Alloy additives weaken the attraction effect.
• Surface quality – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Temperature influence – hot environment weakens magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was assessed with the use of a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, however under shearing force the load capacity is reduced by as much as fivefold. Additionally, even a small distance {between} the magnet and the plate decreases the load capacity.