SM 32x250 [2xM8] / N52 - magnetic separator

Strengths and weaknesses of NdFeB magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• Their power is durable, and after approximately 10 years it drops only by ~1% (according to research),
• Neodymium magnets remain highly resistant to demagnetization caused by external interference,
• The use of an refined coating of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• They show high magnetic induction at the operating surface, which increases their power,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Possibility of custom shaping as well as modifying to precise conditions,
• Universal use in modern technologies – they serve a role in mass storage devices, brushless drives, advanced medical instruments, also other advanced devices.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Drawbacks and weaknesses of neodymium magnets: tips and applications.

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• We recommend a housing - magnetic holder, due to difficulties in realizing nuts inside the magnet and complex forms.
• Possible danger to health – tiny shards of magnets pose a threat, in case of ingestion, which becomes key in the context of child safety. It is also worth noting that small components of these products can disrupt the diagnostic process medical in case of swallowing.
• With large orders the cost of neodymium magnets can be a barrier,

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

The force parameter is a measurement result executed under the following configuration:

• using a plate made of high-permeability steel, acting as a ideal flux conductor
• whose thickness equals approx. 10 mm
• with a surface perfectly flat
• without any insulating layer between the magnet and steel
• during detachment in a direction vertical to the mounting surface
• in temp. approx. 20°C

Magnet lifting force in use – key factors

During everyday use, the actual holding force depends on a number of factors, listed from the most important:

• Distance (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 paint, corrosion or dirt).
• Load vector – highest force is obtained only during perpendicular pulling. The force required to slide of the magnet along the plate is usually many times smaller (approx. 1/5 of the lifting capacity).
• Steel thickness – insufficiently thick plate does not close the flux, causing part of the power to be escaped to the other side.
• Steel type – mild steel attracts best. Alloy admixtures decrease magnetic permeability and lifting capacity.
• Base smoothness – the smoother and more polished the surface, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Operating temperature – NdFeB sinters have a sensitivity to temperature. At higher temperatures they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was measured using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the holding force is lower. In addition, even a slight gap {between} the magnet and the plate lowers the load capacity.