SMZR 32x100 / N52 - magnetic separator with handle

Pros as well as cons of neodymium magnets.

In addition to their magnetic capacity, neodymium magnets provide the following advantages:

• They have constant strength, and over nearly ten years their attraction force decreases symbolically – ~1% (in testing),
• Magnets effectively defend themselves against loss of magnetization caused by external fields,
• In other words, due to the glossy layer of silver, the element becomes visually attractive,
• Magnets are distinguished by exceptionally strong magnetic induction on the working surface,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to the option of accurate shaping and adaptation to specialized requirements, magnetic components can be modeled in a variety of forms and dimensions, which makes them more universal,
• Fundamental importance in high-tech industry – they find application in magnetic memories, electric drive systems, medical equipment, as well as multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which enables their usage in small systems

What to avoid - cons of neodymium magnets and proposals for their use:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only protects the magnet but also increases its resistance to damage
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Limited possibility of creating nuts in the magnet and complicated forms - recommended is a housing - magnet mounting.
• Health risk to health – tiny shards of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child health protection. It is also worth noting that small elements of these devices are able to disrupt the diagnostic process medical after entering the body.
• Due to neodymium price, their price is higher than average,

Maximum holding power of the magnet – what affects it?

Breakaway force was defined for optimal configuration, assuming:

• with the use of a sheet made of special test steel, guaranteeing maximum field concentration
• whose thickness equals approx. 10 mm
• with a surface perfectly flat
• without any clearance between the magnet and steel
• during pulling in a direction perpendicular to the plane
• in temp. approx. 20°C

Lifting capacity in practice – influencing factors

In real-world applications, the actual lifting capacity depends on many variables, presented from the most important:

• Air gap (betwixt the magnet and the plate), because even a microscopic distance (e.g. 0.5 mm) can cause a reduction in force by up to 50% (this also applies to varnish, rust or debris).
• Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet exhibits much less (often approx. 20-30% of nominal force).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal limits the attraction force (the magnet "punches through" it).
• Steel type – low-carbon steel attracts best. Alloy admixtures lower magnetic permeability and lifting capacity.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves force. Rough surfaces weaken the grip.
• Temperature influence – hot environment reduces pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Holding force was measured on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.