SM 32x200 [2xM8] / N42 - magnetic separator

Pros and cons of rare earth magnets.

Apart from their strong magnetic energy, neodymium magnets have these key benefits:

• They have unchanged lifting capacity, and over more than ten years their performance decreases symbolically – ~1% (in testing),
• They feature excellent resistance to magnetism drop when exposed to opposing magnetic fields,
• Thanks to the smooth finish, the layer of nickel, gold, or silver-plated gives an elegant appearance,
• Magnetic induction on the working part of the magnet is maximum,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• Thanks to versatility in shaping and the capacity to adapt to individual projects,
• Universal use in electronics industry – they find application in HDD drives, electromotive mechanisms, precision medical tools, and multitasking production systems.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Drawbacks and weaknesses of neodymium magnets: tips and applications.

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only protects the magnet but also improves 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.
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• Due to limitations in realizing threads and complex shapes in magnets, we propose using casing - magnetic mechanism.
• Health risk resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child safety. It is also worth noting that small components of these products can complicate diagnosis medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which hinders application in large quantities

Highest magnetic holding force – what affects it?

The load parameter shown represents the peak performance, recorded under ideal test conditions, specifically:

• on a block made of mild steel, perfectly concentrating the magnetic flux
• whose transverse dimension equals approx. 10 mm
• with an ideally smooth touching surface
• under conditions of gap-free contact (metal-to-metal)
• during detachment in a direction perpendicular to the mounting surface
• at ambient temperature room level

What influences lifting capacity in practice

Holding efficiency is affected by working environment parameters, including (from most important):

• Distance (betwixt the magnet and the metal), since even a tiny clearance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to varnish, rust or debris).
• Direction of force – highest force is obtained only during pulling at a 90° angle. The force required to slide of the magnet along the plate is standardly many times lower (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Steel grade – ideal substrate is pure iron steel. Cast iron may attract less.
• Surface structure – the smoother and more polished the surface, the better the adhesion and higher the lifting capacity. Roughness acts like micro-gaps.
• Thermal environment – heating the magnet causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.