SM 32x225 [2xM8] / N42 - magnetic separator

Pros and cons of rare earth magnets.

Apart from their superior power, neodymium magnets have these key benefits:

• They do not lose power, even over nearly 10 years – the reduction in strength is only ~1% (according to tests),
• Magnets perfectly resist against demagnetization caused by external fields,
• A magnet with a metallic gold surface has an effective appearance,
• Neodymium magnets ensure maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the form) even at a temperature of 230°C or more...
• Thanks to freedom in designing and the ability to customize to unusual requirements,
• Universal use in future technologies – they serve a role in mass storage devices, electromotive mechanisms, medical equipment, and modern systems.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which makes them useful in miniature devices

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a special holder, which not only secures them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in creating threads and complex shapes in magnets, we propose using a housing - magnetic holder.
• Health risk to health – tiny shards of magnets are risky, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Additionally, small elements of these products can complicate diagnosis medical after entering 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

Maximum magnetic pulling force – what it depends on?

Magnet power is the result of a measurement for ideal contact conditions, taking into account:

• on a base made of mild steel, optimally conducting the magnetic field
• with a thickness of at least 10 mm
• with an polished touching surface
• with zero gap (no coatings)
• for force applied at a right angle (pull-off, not shear)
• at ambient temperature approx. 20 degrees Celsius

Lifting capacity in practice – influencing factors

During everyday use, the actual holding force depends on several key aspects, presented from crucial:

• Distance – existence of foreign body (rust, tape, air) acts as an insulator, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to pulling vertically. When slipping, the magnet exhibits much less (typically approx. 20-30% of nominal force).
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Plate material – mild steel gives the best results. Alloy admixtures lower magnetic permeability and lifting capacity.
• Smoothness – ideal contact is obtained only on smooth steel. Rough texture create air cushions, reducing force.
• Temperature influence – hot environment reduces magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under parallel forces the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet and the plate lowers the lifting capacity.