SM 32x500 [2xM8] / N42 - magnetic separator

Pros as well as cons of neodymium magnets.

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

• They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (in laboratory conditions),
• Neodymium magnets prove to be highly resistant to magnetic field loss caused by magnetic disturbances,
• A magnet with a shiny nickel surface is more attractive,
• Magnetic induction on the surface of the magnet is very high,
• Due to their exceptional temperature resistance, they can operate (depending on the shape) even at temperatures up to 230°C or more,
• Thanks to flexibility in designing and the ability to modify to complex applications,
• Wide application in advanced technology sectors – they are used in HDD drives, electric drive systems, advanced medical instruments, also technologically advanced constructions.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• Brittleness is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a strong case, which not only secures them against impacts but also increases their durability
• Neodymium magnets lose their strength 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material resistant to moisture, when using outdoors
• Limited ability of creating nuts in the magnet and complicated forms - preferred is a housing - magnetic holder.
• Possible danger related to microscopic parts of magnets are risky, if swallowed, which gains importance in the context of child safety. Additionally, tiny parts of these magnets can complicate diagnosis medical in case of swallowing.
• Due to neodymium price, their price exceeds standard values,

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

The force parameter is a result of laboratory testing performed under specific, ideal conditions:

• using a base made of mild steel, acting as a magnetic yoke
• whose thickness is min. 10 mm
• characterized by even structure
• with total lack of distance (no coatings)
• during detachment in a direction vertical to the mounting surface
• at ambient temperature approx. 20 degrees Celsius

What influences lifting capacity in practice

Bear in mind that the magnet holding may be lower subject to elements below, starting with the most relevant:

• Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Loading method – catalog parameter refers to pulling vertically. When slipping, the magnet holds much less (often approx. 20-30% of maximum force).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Material type – ideal substrate is high-permeability steel. Hardened steels may generate lower lifting capacity.
• Surface structure – the more even the surface, the larger the contact zone and stronger the hold. Unevenness creates an air distance.
• Thermal factor – high temperature weakens pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under a perpendicular pulling force, whereas under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet’s surface and the plate reduces the holding force.