SMZR 25x150 / N52 - magnetic separator with handle

Strengths as well as weaknesses of neodymium magnets.

Besides their remarkable field intensity, neodymium magnets offer the following advantages:

• Their power remains stable, and after approximately ten years it decreases only by ~1% (according to research),
• They retain their magnetic properties even under strong external field,
• By applying a lustrous layer of silver, the element has an nice look,
• Magnetic induction on the working layer of the magnet is maximum,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of precise creating and modifying to individual applications,
• Wide application in high-tech industry – they are used in hard drives, electromotive mechanisms, diagnostic systems, as well as technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we suggest using special steel housings. 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 weakening of strength (a factor is the shape and 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• We recommend casing - magnetic mechanism, due to difficulties in creating threads inside the magnet and complicated forms.
• Possible danger to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which becomes key in the context of child safety. Additionally, tiny parts of these magnets are able to be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Highest magnetic holding force – what affects it?

Holding force of 0 kg is a theoretical maximum value conducted under standard conditions:

• with the application of a yoke made of special test steel, ensuring full magnetic saturation
• possessing a thickness of minimum 10 mm to avoid saturation
• with a plane cleaned and smooth
• without any insulating layer between the magnet and steel
• during pulling in a direction perpendicular to the plane
• at standard ambient temperature

Lifting capacity in real conditions – factors

In real-world applications, the actual holding force results from a number of factors, presented from most significant:

• Distance – existence of foreign body (rust, dirt, gap) acts as an insulator, which lowers power steeply (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet exhibits much less (often approx. 20-30% of maximum force).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Material composition – not every steel attracts identically. High carbon content worsen the interaction with the magnet.
• Plate texture – smooth surfaces guarantee perfect abutment, which improves field saturation. Uneven metal reduce efficiency.
• Thermal environment – temperature increase causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity was assessed with the use of a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under shearing force the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.