SM 25x100 [2xM8] / N42 - magnetic separator

Strengths and weaknesses of NdFeB magnets.

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

• Their magnetic field is durable, and after around ten years it drops only by ~1% (according to research),
• They maintain their magnetic properties even under close interference source,
• The use of an aesthetic layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Neodymium magnets generate maximum magnetic induction on a their surface, which allows for strong attraction,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Thanks to the possibility of free shaping and customization to specialized solutions, neodymium magnets can be manufactured in a broad palette of forms and dimensions, which amplifies use scope,
• Fundamental importance in innovative solutions – they are commonly used in magnetic memories, drive modules, diagnostic systems, and industrial machines.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a special holder, which not only protects them against impacts but also increases their durability
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• We recommend casing - magnetic mount, due to difficulties in realizing threads inside the magnet and complicated shapes.
• Potential hazard related to microscopic parts of magnets are risky, when accidentally swallowed, which is particularly important in the context of child health protection. Additionally, small elements of these products can be problematic in diagnostics medical when they are in the body.
• Due to expensive raw materials, their price is higher than average,

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

Breakaway force is the result of a measurement for ideal contact conditions, assuming:

• with the use of a yoke made of low-carbon steel, ensuring maximum field concentration
• with a cross-section no less than 10 mm
• with a plane cleaned and smooth
• under conditions of ideal adhesion (metal-to-metal)
• during pulling in a direction perpendicular to the plane
• in temp. approx. 20°C

Practical lifting capacity: influencing factors

Bear in mind that the application force will differ depending on elements below, starting with the most relevant:

• Gap between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Force direction – declared lifting capacity refers to detachment vertically. When applying parallel force, the magnet holds much less (often approx. 20-30% of nominal force).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of generating force.
• Metal type – not every steel reacts the same. High carbon content worsen the attraction effect.
• Plate texture – smooth surfaces guarantee perfect abutment, which increases force. Rough surfaces reduce efficiency.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, however under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a small distance {between} the magnet and the plate decreases the lifting capacity.