SM 32x325 [2xM8] / N52 - magnetic separator

Strengths as well as weaknesses of rare earth magnets.

Apart from their notable magnetic energy, neodymium magnets have these key benefits:

• They have constant strength, and over more than 10 years their performance decreases symbolically – ~1% (according to theory),
• Neodymium magnets are exceptionally resistant to magnetic field loss caused by external magnetic fields,
• A magnet with a shiny gold surface looks better,
• Magnets exhibit excellent magnetic induction on the outer layer,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of exact machining as well as modifying to precise conditions,
• Versatile presence in innovative solutions – they are used in HDD drives, electric motors, advanced medical instruments, also other advanced devices.
• Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,

What to avoid - cons of neodymium magnets: tips and applications.

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a steel housing, which not only secures them against impacts but also raises their durability
• Neodymium magnets lose their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation and corrosion.
• Due to limitations in creating nuts and complex forms in magnets, we propose using casing - magnetic mechanism.
• Potential hazard to health – tiny shards of magnets pose a threat, if swallowed, which becomes key in the context of child safety. It is also worth noting that small elements of these devices can complicate diagnosis medical in case of swallowing.
• With large orders the cost of neodymium magnets is economically unviable,

Magnetic strength at its maximum – what contributes to it?

Breakaway force was determined for optimal configuration, taking into account:

• using a sheet made of low-carbon steel, functioning as a magnetic yoke
• whose thickness reaches at least 10 mm
• characterized by lack of roughness
• under conditions of no distance (surface-to-surface)
• during detachment in a direction vertical to the plane
• in temp. approx. 20°C

Determinants of practical lifting force of a magnet

During everyday use, the real power results from several key aspects, presented from the most important:

• Gap between magnet and steel – every millimeter of separation (caused e.g. by veneer or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is available only during perpendicular pulling. The force required to slide of the magnet along the plate is usually many times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Plate material – low-carbon steel attracts best. Alloy steels decrease magnetic properties and holding force.
• Surface structure – the more even the plate, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Thermal factor – high temperature weakens magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity testing was conducted on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, in contrast under shearing force the load capacity is reduced by as much as 75%. Additionally, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.