SM 32x150 [2xM8] / N52 - magnetic separator

Pros and cons of neodymium magnets.

Besides their exceptional strength, neodymium magnets offer the following advantages:

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• They are noted for resistance to demagnetization induced by external disturbances,
• By using a shiny layer of gold, the element acquires an proper look,
• The surface of neodymium magnets generates a maximum magnetic field – this is one of their assets,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling functioning at temperatures approaching 230°C and above...
• Due to the possibility of precise molding and customization to unique needs, neodymium magnets can be created in a wide range of geometric configurations, which expands the range of possible applications,
• Wide application in advanced technology sectors – they serve a role in magnetic memories, electric motors, diagnostic systems, and complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which makes them useful in small systems

Problematic aspects of neodymium magnets: application proposals

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only shields the magnet but also improves its resistance to damage
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• We recommend cover - magnetic holder, due to difficulties in realizing threads inside the magnet and complicated forms.
• Possible danger to health – tiny shards of magnets can be dangerous, if swallowed, which is particularly important in the aspect of protecting the youngest. Furthermore, small elements of these devices can be problematic in diagnostics medical in case of swallowing.
• With mass production the cost of neodymium magnets is a challenge,

Highest magnetic holding force – what it depends on?

The specified lifting capacity concerns the maximum value, measured under optimal environment, namely:

• with the application of a yoke made of special test steel, ensuring maximum field concentration
• possessing a thickness of minimum 10 mm to avoid saturation
• with an polished touching surface
• without the slightest insulating layer between the magnet and steel
• during pulling in a direction vertical to the mounting surface
• in neutral thermal conditions

Determinants of lifting force in real conditions

Please note that the magnet holding may be lower influenced by elements below, starting with the most relevant:

• Space between magnet and steel – every millimeter of separation (caused e.g. by veneer or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
• Direction of force – highest force is reached only during pulling at a 90° angle. The force required to slide of the magnet along the surface is typically many times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Material composition – different alloys attracts identically. High carbon content worsen the interaction with the magnet.
• Plate texture – ground elements guarantee perfect abutment, which improves field saturation. Rough surfaces reduce efficiency.
• Temperature influence – hot environment reduces pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under parallel forces the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet and the plate lowers the lifting capacity.