SM 25x325 [2xM8] / N52 - magnetic separator

Pros as well as cons of NdFeB magnets.

Apart from their consistent magnetism, neodymium magnets have these key benefits:

• They have constant strength, and over around ten years their attraction force decreases symbolically – ~1% (according to theory),
• They feature excellent resistance to weakening of magnetic properties as a result of opposing magnetic fields,
• By applying a reflective layer of gold, the element has an modern look,
• Neodymium magnets generate maximum magnetic induction on a small area, which increases force concentration,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• In view of the possibility of flexible molding and customization to custom projects, neodymium magnets can be modeled in a variety of forms and dimensions, which amplifies use scope,
• Fundamental importance in modern technologies – they are utilized in magnetic memories, brushless drives, advanced medical instruments, as well as multitasking production systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• To avoid cracks under impact, we recommend using special steel housings. Such a solution secures the magnet and simultaneously improves its durability.
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their strength 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 usually rust. To use them in conditions 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 producing nuts and complicated forms in magnets, we propose using casing - magnetic mechanism.
• Health risk to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the context of child safety. Furthermore, small components of these devices are able to be problematic in diagnostics medical in case of swallowing.
• With budget limitations the cost of neodymium magnets can be a barrier,

Maximum magnetic pulling force – what affects it?

Breakaway force was determined for ideal contact conditions, including:

• using a base made of low-carbon steel, acting as a circuit closing element
• with a thickness of at least 10 mm
• characterized by lack of roughness
• under conditions of gap-free contact (metal-to-metal)
• for force acting at a right angle (in the magnet axis)
• at standard ambient temperature

Determinants of practical lifting force of a magnet

During everyday use, the real power depends on several key aspects, listed from most significant:

• Distance (between the magnet and the plate), as even a microscopic distance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Angle of force application – maximum parameter is reached only during perpendicular pulling. The force required to slide of the magnet along the plate is standardly many times smaller (approx. 1/5 of the lifting capacity).
• Wall thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of converting into lifting capacity.
• Steel grade – the best choice is pure iron steel. Stainless steels may have worse magnetic properties.
• Surface finish – ideal contact is possible only on smooth steel. Any scratches and bumps create air cushions, weakening the magnet.
• Temperature – temperature increase causes a temporary drop of induction. Check the thermal limit for a given model.

* Lifting capacity was determined using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the holding force is lower. Moreover, even a minimal clearance {between} the magnet and the plate lowers the lifting capacity.