SM 18x100 [2xM5] / N42 - magnetic separator

Pros and cons of NdFeB magnets.

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

• They have unchanged lifting capacity, and over around 10 years their performance decreases symbolically – ~1% (according to theory),
• They retain their magnetic properties even under close interference source,
• In other words, due to the glossy finish of gold, the element gains visual value,
• The surface of neodymium magnets generates a maximum magnetic field – this is a key feature,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to the possibility of accurate forming and adaptation to unique projects, NdFeB magnets can be manufactured in a variety of geometric configurations, which amplifies use scope,
• Significant place in innovative solutions – they are utilized in data components, drive modules, advanced medical instruments, as well as modern systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only shields the magnet but also improves its resistance to damage
• Neodymium magnets decrease their power 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 stability even at temperatures up to 230°C
• They oxidize in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Due to limitations in realizing nuts and complex shapes in magnets, we propose using casing - magnetic mechanism.
• Possible danger to health – tiny shards of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child safety. Additionally, small components of these products can be problematic in diagnostics medical after entering the body.
• Due to complex production process, their price is higher than average,

Maximum holding power of the magnet – what affects it?

The declared magnet strength represents the peak performance, recorded under laboratory conditions, namely:

• with the contact of a sheet made of special test steel, guaranteeing maximum field concentration
• possessing a massiveness of min. 10 mm to ensure full flux closure
• characterized by smoothness
• under conditions of gap-free contact (metal-to-metal)
• for force applied at a right angle (in the magnet axis)
• in neutral thermal conditions

Lifting capacity in practice – influencing factors

It is worth knowing that the application force will differ subject to elements below, starting with the most relevant:

• Space between magnet and steel – every millimeter of separation (caused e.g. by veneer or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Metal type – not every steel reacts the same. Alloy additives weaken the interaction with the magnet.
• Surface finish – ideal contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Thermal environment – temperature increase causes a temporary drop of induction. Check the maximum operating temperature for a given model.

* Lifting capacity was assessed by applying a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, however under parallel forces the load capacity is reduced by as much as fivefold. Additionally, even a small distance {between} the magnet and the plate decreases the lifting capacity.