SMZR 32x225 / N52 - magnetic separator with handle

Advantages as well as disadvantages of neodymium magnets.

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

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• Magnets effectively defend themselves against demagnetization caused by ambient magnetic noise,
• The use of an elegant layer of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Neodymium magnets create maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• Thanks to the potential of free forming and customization to specialized needs, neodymium magnets can be modeled in a wide range of forms and dimensions, which makes them more universal,
• Versatile presence in modern industrial fields – they are used in HDD drives, brushless drives, advanced medical instruments, as well as other advanced devices.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Problematic aspects of neodymium magnets: application proposals

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can break. We advise keeping them in a special holder, which not only protects them against impacts but also increases their durability
• Neodymium magnets decrease their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• We recommend a housing - magnetic holder, due to difficulties in realizing threads inside the magnet and complex forms.
• Possible danger to health – tiny shards of magnets are risky, if swallowed, which is particularly important in the context of child safety. It is also worth noting that small elements of these magnets are able to complicate diagnosis medical after entering the body.
• Due to complex production process, their price is relatively high,

Optimal lifting capacity of a neodymium magnet – what affects it?

The declared magnet strength refers to the peak performance, recorded under ideal test conditions, namely:

• with the application of a yoke made of low-carbon steel, guaranteeing full magnetic saturation
• with a thickness of at least 10 mm
• characterized by even structure
• under conditions of no distance (metal-to-metal)
• during pulling in a direction vertical to the plane
• at ambient temperature room level

Practical lifting capacity: influencing factors

Please note that the application force will differ depending on the following factors, starting with the most relevant:

• Distance (betwixt the magnet and the plate), since even a very small distance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to varnish, rust or debris).
• Load vector – maximum parameter is available only during pulling at a 90° angle. The shear force of the magnet along the plate is typically many times smaller (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin steel causes magnetic saturation, causing part of the power to be lost to the other side.
• Chemical composition of the base – low-carbon steel attracts best. Alloy steels decrease magnetic permeability and lifting capacity.
• Surface quality – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Roughness acts like micro-gaps.
• Thermal factor – hot environment reduces magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity was determined by applying a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, however under parallel forces the load capacity is reduced by as much as 5 times. Moreover, even a minimal clearance {between} the magnet and the plate decreases the holding force.