SM 25x225 [2xM8] / N42 - magnetic separator

Pros as well as cons of rare earth magnets.

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

• Their magnetic field remains stable, and after around ten years it decreases only by ~1% (according to research),
• They are extremely resistant to demagnetization induced by external disturbances,
• In other words, due to the smooth finish of nickel, the element becomes visually attractive,
• The surface of neodymium magnets generates a concentrated magnetic field – this is a distinguishing feature,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to the ability of flexible molding and customization to custom solutions, magnetic components can be produced in a wide range of geometric configurations, which amplifies use scope,
• Wide application in innovative solutions – they are utilized in mass storage devices, electromotive mechanisms, advanced medical instruments, also multitasking production systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, in miniature format,

What to avoid - cons of neodymium magnets and ways of using them

• Brittleness is one of their disadvantages. Upon intense impact they can break. We recommend keeping them in a special holder, which not only protects them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets suffer a drop in strength. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 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 resistant to moisture, when using outdoors
• Limited ability of making threads in the magnet and complex shapes - recommended is a housing - mounting mechanism.
• Possible danger resulting from small fragments of magnets can be dangerous, in case of ingestion, which becomes key in the context of child safety. Additionally, small components of these magnets are able to complicate diagnosis medical when they are in the body.
• Due to complex production process, their price is higher than average,

Maximum lifting capacity of the magnet – what it depends on?

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

• on a plate made of mild steel, perfectly concentrating the magnetic flux
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with a plane perfectly flat
• with direct contact (no coatings)
• under axial force vector (90-degree angle)
• at temperature room level

Determinants of lifting force in real conditions

In practice, the actual lifting capacity results from a number of factors, listed from most significant:

• Clearance – the presence of any layer (paint, tape, air) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Force direction – catalog parameter refers to detachment vertically. When slipping, the magnet holds much less (often approx. 20-30% of nominal force).
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Steel grade – ideal substrate is pure iron steel. Hardened steels may generate lower lifting capacity.
• Surface quality – the smoother and more polished the surface, the better the adhesion and higher the lifting capacity. Roughness acts like micro-gaps.
• Thermal environment – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under perpendicular forces, in contrast under shearing force the load capacity is reduced by as much as 75%. Additionally, even a small distance {between} the magnet and the plate decreases the holding force.