SM 32x350 [2xM8] / N42 - magnetic separator

Pros and cons of NdFeB magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They retain magnetic properties for almost 10 years – the loss is just ~1% (in theory),
• They are noted for resistance to demagnetization induced by presence of other magnetic fields,
• In other words, due to the shiny surface of nickel, the element is aesthetically pleasing,
• Neodymium magnets ensure maximum magnetic induction on a their surface, which allows for strong attraction,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• Thanks to freedom in shaping and the capacity to modify to individual projects,
• Universal use in high-tech industry – they serve a role in mass storage devices, electric drive systems, medical equipment, as well as modern systems.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Cons of neodymium magnets and ways of using them

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution protects the magnet and simultaneously increases its durability.
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore when using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing threads and complicated forms in magnets, we recommend using a housing - magnetic mount.
• Health risk related to microscopic parts of magnets pose a threat, in case of ingestion, which is particularly important in the context of child safety. Additionally, tiny parts of these devices can disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets cost more 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 force parameter is a result of laboratory testing executed under the following configuration:

• with the use of a yoke made of low-carbon steel, ensuring full magnetic saturation
• with a thickness no less than 10 mm
• with an ideally smooth touching surface
• with direct contact (without impurities)
• under axial force vector (90-degree angle)
• in stable room temperature

Practical lifting capacity: influencing factors

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

• Air gap (between the magnet and the metal), because even a very small clearance (e.g. 0.5 mm) can cause a decrease in force by up to 50% (this also applies to paint, corrosion or dirt).
• Loading method – declared lifting capacity refers to pulling vertically. When applying parallel force, the magnet exhibits much less (typically approx. 20-30% of nominal force).
• Steel thickness – insufficiently thick sheet does not close the flux, causing part of the flux to be wasted to the other side.
• Material type – ideal substrate is high-permeability steel. Stainless steels may generate lower lifting capacity.
• Smoothness – full contact is possible only on smooth steel. Rough texture reduce the real contact area, reducing force.
• Thermal environment – heating the magnet causes a temporary drop of force. Check the thermal limit for a given model.

* Lifting capacity was determined with the use of a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, in contrast under shearing force the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate reduces the load capacity.