SM 32x500 [2xM8] / N42 - magnetic separator

Pros and cons of neodymium magnets.

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

• They do not lose strength, even during around 10 years – the drop in lifting capacity is only ~1% (based on measurements),
• Magnets perfectly resist against demagnetization caused by ambient magnetic noise,
• In other words, due to the smooth finish of gold, the element is aesthetically pleasing,
• Magnetic induction on the surface of the magnet turns out to be extremely intense,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to modularity in designing and the capacity to modify to unusual requirements,
• Huge importance in future technologies – they are utilized in computer drives, drive modules, precision medical tools, and modern systems.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Disadvantages of neodymium magnets:

• To avoid cracks under impact, we suggest using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• They rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing threads and complicated forms in magnets, we propose using a housing - magnetic mount.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child health protection. Additionally, small components of these products are able to be problematic in diagnostics medical after entering the body.
• With mass production the cost of neodymium magnets is economically unviable,

Best holding force of the magnet in ideal parameters – what contributes to it?

Holding force of 0 kg is a theoretical maximum value conducted under specific, ideal conditions:

• on a plate made of mild steel, effectively closing the magnetic flux
• possessing a thickness of minimum 10 mm to ensure full flux closure
• with an polished contact surface
• with total lack of distance (without coatings)
• during pulling in a direction vertical to the plane
• in stable room temperature

Practical aspects of lifting capacity – factors

It is worth knowing that the working load will differ subject to the following factors, in order of importance:

• Clearance – existence of foreign body (rust, tape, gap) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Load vector – highest force is reached only during perpendicular pulling. The force required to slide of the magnet along the surface is usually many times smaller (approx. 1/5 of the lifting capacity).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Metal type – not every steel attracts identically. Alloy additives worsen the interaction with the magnet.
• Smoothness – full contact is possible only on polished steel. Any scratches and bumps create air cushions, reducing force.
• Heat – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and in frost gain strength (up to a certain limit).

* Holding force was checked on the plate surface of 20 mm thickness, when a perpendicular force was applied, however under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the load capacity.