SM 25x100 [2xM8] / N52 - magnetic separator

Pros and cons of NdFeB magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They have constant strength, and over nearly 10 years their performance decreases symbolically – ~1% (according to theory),
• They are resistant to demagnetization induced by presence of other magnetic fields,
• Thanks to the glossy finish, the surface of nickel, gold-plated, or silver gives an clean appearance,
• Magnetic induction on the top side of the magnet remains exceptional,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of individual forming as well as modifying to concrete requirements,
• Fundamental importance in electronics industry – they find application in data components, electromotive mechanisms, precision medical tools, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which makes them useful in miniature devices

Disadvantages of neodymium magnets:

• They are fragile upon heavy 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 reduce 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 waterproof magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in creating threads and complicated shapes in magnets, we propose using casing - magnetic mechanism.
• Potential hazard to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, small elements of these products are able to disrupt the diagnostic process 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

Detachment force of the magnet in optimal conditions – what contributes to it?

Magnet power is the result of a measurement for the most favorable conditions, taking into account:

• using a sheet made of low-carbon steel, serving as a magnetic yoke
• with a thickness of at least 10 mm
• with a surface cleaned and smooth
• without any air gap between the magnet and steel
• for force acting at a right angle (in the magnet axis)
• at conditions approx. 20°C

Lifting capacity in practice – influencing factors

In real-world applications, the real power results from several key aspects, listed from the most important:

• Air gap (between the magnet and the plate), since even a tiny clearance (e.g. 0.5 mm) can cause a drastic drop in force by up to 50% (this also applies to varnish, rust or debris).
• Direction of force – highest force is reached only during perpendicular pulling. The force required to slide of the magnet along the plate is typically many times lower (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Plate material – mild steel attracts best. Alloy admixtures decrease magnetic permeability and holding force.
• Surface condition – ground elements guarantee perfect abutment, which increases force. Rough surfaces weaken the grip.
• Temperature influence – high temperature weakens magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under perpendicular forces, however under attempts to slide the magnet the load capacity is reduced by as much as fivefold. In addition, even a slight gap {between} the magnet and the plate lowers the holding force.