SM 25x200 [2xM8] / N52 - magnetic separator

Advantages as well as disadvantages of neodymium magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They have constant strength, and over nearly 10 years their performance decreases symbolically – ~1% (according to theory),
• They have excellent resistance to magnetism drop when exposed to external magnetic sources,
• The use of an refined coating of noble metals (nickel, gold, silver) causes the element to look better,
• Magnetic induction on the working layer of the magnet turns out to be very high,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and are able to act (depending on the shape) even at a temperature of 230°C or more...
• Possibility of individual modeling and modifying to concrete needs,
• Significant place in future technologies – they are used in mass storage devices, electric motors, precision medical tools, as well as modern systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, in miniature format,

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• 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
• Limited possibility of producing nuts in the magnet and complicated forms - preferred is cover - mounting mechanism.
• Potential hazard related to microscopic parts of magnets pose a threat, in case of ingestion, which gains importance in the context of child health protection. Additionally, tiny parts of these magnets can disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which hinders application in large quantities

Detachment force of the magnet in optimal conditions – what affects it?

Magnet power is the result of a measurement for the most favorable conditions, taking into account:

• using a sheet made of high-permeability steel, serving as a circuit closing element
• possessing a massiveness of min. 10 mm to ensure full flux closure
• characterized by even structure
• with direct contact (without paint)
• under perpendicular force direction (90-degree angle)
• at room temperature

Lifting capacity in practice – influencing factors

Please note that the application force will differ subject to the following factors, in order of importance:

• Clearance – the presence of any layer (rust, tape, gap) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Loading method – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet exhibits much less (typically approx. 20-30% of nominal force).
• Substrate thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Steel type – low-carbon steel gives the best results. Alloy steels decrease magnetic properties and lifting capacity.
• Plate texture – smooth surfaces guarantee perfect abutment, which improves force. Uneven metal reduce efficiency.
• Thermal environment – temperature increase results in weakening of induction. Check the thermal limit for a given model.

* Lifting capacity was assessed using a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.