SM 18x300 [2xM5] / N42 - magnetic separator

Advantages and disadvantages of NdFeB magnets.

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

• Their power is maintained, and after around ten years it drops only by ~1% (theoretically),
• They are extremely resistant to demagnetization induced by external magnetic fields,
• A magnet with a metallic nickel surface looks better,
• Neodymium magnets achieve maximum magnetic induction on a small area, which allows for strong attraction,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• Thanks to flexibility in shaping and the capacity to modify to complex applications,
• Fundamental importance in modern industrial fields – they are commonly used in HDD drives, brushless drives, precision medical tools, as well as multitasking production systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• To avoid cracks under impact, we recommend using special steel holders. Such a solution secures the magnet and simultaneously improves its durability.
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 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 prevent oxidation and corrosion.
• We recommend casing - magnetic mount, due to difficulties in creating nuts inside the magnet and complicated shapes.
• Possible danger resulting from small fragments of magnets can be dangerous, if swallowed, which gains importance in the context of child safety. Additionally, small elements of these devices are able to disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

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

The specified lifting capacity refers to the peak performance, measured under laboratory conditions, specifically:

• with the use of a yoke made of special test steel, ensuring full magnetic saturation
• with a thickness of at least 10 mm
• with an ground contact surface
• under conditions of no distance (surface-to-surface)
• during detachment in a direction vertical to the mounting surface
• at conditions approx. 20°C

Determinants of practical lifting force of a magnet

Bear in mind that the application force may be lower influenced by elements below, in order of importance:

• Clearance – existence of foreign body (paint, dirt, gap) acts as an insulator, which reduces power steeply (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet exhibits significantly lower power (typically approx. 20-30% of nominal force).
• Plate thickness – insufficiently thick sheet does not accept the full field, causing part of the power to be lost into the air.
• Chemical composition of the base – low-carbon steel attracts best. Higher carbon content reduce magnetic permeability and lifting capacity.
• Surface quality – the more even the surface, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Temperature influence – hot environment reduces pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was conducted on plates with a smooth surface of optimal thickness, under perpendicular forces, 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 lifting capacity.