SM 32x300 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of NdFeB magnets.

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

• They do not lose magnetism, even after around ten years – the drop in power is only ~1% (theoretically),
• They maintain their magnetic properties even under close interference source,
• In other words, due to the aesthetic finish of nickel, the element gains a professional look,
• Magnetic induction on the surface of the magnet is exceptional,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, allowing for action at temperatures approaching 230°C and above...
• Thanks to modularity in shaping and the capacity to adapt to individual projects,
• Huge importance in electronics industry – they serve a role in mass storage devices, electric motors, advanced medical instruments, as well as other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which allows their use in small systems

Cons of neodymium magnets and proposals for their use:

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• Neodymium magnets lose their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Limited possibility of making threads in the magnet and complex forms - recommended is casing - mounting mechanism.
• Possible danger resulting from small fragments of magnets are risky, in case of ingestion, which gains importance in the context of child safety. Furthermore, small components of these products can complicate diagnosis medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Breakaway strength of the magnet in ideal conditions – what contributes to it?

The declared magnet strength refers to the peak performance, obtained under ideal test conditions, meaning:

• using a sheet made of high-permeability steel, acting as a ideal flux conductor
• with a cross-section no less than 10 mm
• characterized by even structure
• with zero gap (without coatings)
• during detachment in a direction perpendicular to the mounting surface
• in temp. approx. 20°C

Lifting capacity in real conditions – factors

Holding efficiency is affected by specific conditions, including (from priority):

• Distance (betwixt the magnet and the plate), as even a tiny distance (e.g. 0.5 mm) results in a reduction in force by up to 50% (this also applies to varnish, corrosion or dirt).
• Force direction – remember that the magnet holds strongest perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Element thickness – for full efficiency, the steel must be adequately massive. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Metal type – different alloys attracts identically. Alloy additives worsen the interaction with the magnet.
• Base smoothness – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Roughness creates an air distance.
• Thermal factor – hot environment weakens pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was measured by applying a polished steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, however under attempts to slide the magnet the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate reduces the load capacity.