SMZR 32x200 / N52 - magnetic separator with handle

Advantages as well as disadvantages of rare earth magnets.

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

• Their magnetic field is maintained, and after around ten years it decreases only by ~1% (theoretically),
• They have excellent resistance to magnetism drop due to external fields,
• Thanks to the elegant finish, the coating of nickel, gold-plated, or silver-plated gives an elegant appearance,
• Magnets possess exceptionally strong magnetic induction on the working surface,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to versatility in forming and the ability to customize to client solutions,
• Significant place in innovative solutions – they are commonly used in mass storage devices, brushless drives, advanced medical instruments, also technologically advanced constructions.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

Disadvantages of NdFeB magnets:

• At strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets decrease 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
• When exposed to humidity, magnets start to 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 threads and complex forms in magnets, we propose using cover - magnetic mechanism.
• Potential hazard to health – tiny shards of magnets pose a threat, when accidentally swallowed, which gains importance in the context of child health protection. Furthermore, small components of these magnets can complicate diagnosis medical when they are in the body.
• Due to neodymium price, their price is higher than average,

Maximum lifting force for a neodymium magnet – what affects it?

The load parameter shown refers to the peak performance, measured under laboratory conditions, meaning:

• on a block made of mild steel, optimally conducting the magnetic flux
• whose thickness is min. 10 mm
• with a surface free of scratches
• under conditions of ideal adhesion (surface-to-surface)
• during pulling in a direction perpendicular to the plane
• at temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

It is worth knowing that the working load may be lower depending on elements below, in order of importance:

• Distance – the presence of any layer (rust, tape, air) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Force direction – remember that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Plate thickness – insufficiently thick steel does not close the flux, causing part of the flux to be lost to the other side.
• Chemical composition of the base – mild steel gives the best results. Alloy steels lower magnetic permeability and lifting capacity.
• Plate texture – ground elements ensure maximum contact, which improves force. Uneven metal weaken the grip.
• Temperature – heating the magnet results in weakening of induction. Check the maximum operating temperature for a given model.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under a perpendicular pulling force, however under attempts to slide the magnet the holding force is lower. In addition, even a small distance {between} the magnet and the plate decreases the lifting capacity.