SM 32x275 [2xM8] / N52 - magnetic separator

Pros and cons of NdFeB magnets.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They retain full power for nearly ten years – the drop is just ~1% (based on simulations),
• They feature excellent resistance to magnetic field loss due to external fields,
• The use of an aesthetic finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Magnets are characterized by exceptionally strong magnetic induction on the surface,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• In view of the option of accurate forming and customization to specialized projects, magnetic components can be manufactured in a wide range of geometric configurations, which expands the range of possible applications,
• Significant place in innovative solutions – they serve a role in hard drives, electric motors, medical equipment, also complex engineering applications.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Problematic aspects of neodymium magnets: tips and applications.

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only protects the magnet but also increases its resistance to damage
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in creating nuts and complex shapes in magnets, we recommend using cover - magnetic holder.
• Health risk related to microscopic parts of magnets are risky, in case of ingestion, which is particularly important in the context of child health protection. It is also worth noting that tiny parts of these devices can complicate diagnosis medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum holding power of the magnet – what contributes to it?

Breakaway force was determined for ideal contact conditions, taking into account:

• with the contact of a sheet made of special test steel, ensuring maximum field concentration
• with a thickness no less than 10 mm
• characterized by even structure
• without any clearance between the magnet and steel
• during pulling in a direction vertical to the plane
• at standard ambient temperature

Determinants of lifting force in real conditions

During everyday use, the real power results from a number of factors, ranked from crucial:

• Space between magnet and steel – every millimeter of distance (caused e.g. by veneer or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is obtained only during pulling at a 90° angle. The shear force of the magnet along the plate is usually several times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Plate material – low-carbon steel gives the best results. Alloy steels reduce magnetic permeability and lifting capacity.
• Surface condition – smooth surfaces guarantee perfect abutment, which increases field saturation. Rough surfaces reduce efficiency.
• Thermal environment – heating the magnet results in weakening of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity was assessed using a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, in contrast under parallel forces the holding force is lower. Additionally, even a minimal clearance {between} the magnet and the plate lowers the holding force.