SM 25x175 [2xM8] / N52 - magnetic separator

Pros and cons of rare earth magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• Their power is durable, and after approximately 10 years it drops only by ~1% (according to research),
• Neodymium magnets remain extremely resistant to magnetic field loss caused by external magnetic fields,
• A magnet with a metallic gold surface has an effective appearance,
• They show high magnetic induction at the operating surface, making them more effective,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling functioning at temperatures reaching 230°C and above...
• Possibility of accurate creating as well as adjusting to defined needs,
• Versatile presence in innovative solutions – they are commonly used in hard drives, motor assemblies, medical equipment, as well as complex engineering applications.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which makes them useful in compact constructions

Problematic aspects of neodymium magnets: tips and applications.

• Brittleness is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a special holder, which not only secures them against impacts but also raises their durability
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• We recommend a housing - magnetic mount, due to difficulties in realizing threads inside the magnet and complicated forms.
• Health risk to health – tiny shards of magnets are risky, in case of ingestion, which becomes key in the aspect of protecting the youngest. Additionally, small elements of these magnets are able to disrupt the diagnostic process medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum lifting capacity of the magnet – what contributes to it?

The specified lifting capacity represents the maximum value, recorded under ideal test conditions, meaning:

• with the use of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• possessing a thickness of minimum 10 mm to avoid saturation
• with a surface cleaned and smooth
• with direct contact (without paint)
• for force acting at a right angle (in the magnet axis)
• in stable room temperature

Practical aspects of lifting capacity – factors

During everyday use, the actual lifting capacity is determined by several key aspects, listed from crucial:

• Clearance – the presence of foreign body (rust, tape, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Angle of force application – maximum parameter is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the plate is usually several times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Chemical composition of the base – mild steel gives the best results. Alloy admixtures reduce magnetic permeability and holding force.
• Base smoothness – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Roughness creates an air distance.
• Heat – neodymium magnets have a sensitivity to temperature. At higher temperatures they are weaker, and in frost gain strength (up to a certain limit).

* Holding force was tested on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, whereas 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 holding force.