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

Advantages as well as disadvantages of neodymium magnets.

Besides their immense field intensity, neodymium magnets offer the following advantages:

• They retain full power for nearly 10 years – the loss is just ~1% (according to analyses),
• Neodymium magnets remain remarkably resistant to loss of magnetic properties caused by external magnetic fields,
• Thanks to the shiny finish, the plating of nickel, gold, or silver-plated gives an aesthetic appearance,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of precise machining as well as adapting to concrete requirements,
• Versatile presence in advanced technology sectors – they are utilized in mass storage devices, electric drive systems, precision medical tools, as well as technologically advanced constructions.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Problematic aspects of neodymium magnets: tips and applications.

• Brittleness is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a special holder, which not only protects them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets experience a drop in strength. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in producing nuts and complex shapes in magnets, we propose using casing - magnetic mount.
• Health risk related to microscopic parts of magnets pose a threat, in case of ingestion, which is particularly important in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products are able to disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

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

The force parameter is a measurement result conducted under standard conditions:

• with the use of a sheet made of special test steel, ensuring full magnetic saturation
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by even structure
• with direct contact (no coatings)
• during pulling in a direction vertical to the plane
• at temperature room level

Impact of factors on magnetic holding capacity in practice

In practice, the actual holding force depends on several key aspects, presented from most significant:

• Gap between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Angle of force application – highest force is obtained only during perpendicular pulling. The shear force of the magnet along the plate is standardly many times lower (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Material composition – not every steel reacts the same. High carbon content worsen the attraction effect.
• Surface finish – full contact is possible only on polished steel. Any scratches and bumps create air cushions, reducing force.
• Temperature influence – hot environment weakens magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under perpendicular forces, in contrast under shearing force the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet’s surface and the plate lowers the lifting capacity.