SM 18x125 [2xM5] / N42 - magnetic separator

Strengths as well as weaknesses of neodymium magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They virtually do not lose power, because even after ten years the performance loss is only ~1% (based on calculations),
• They possess excellent resistance to magnetism drop when exposed to external magnetic sources,
• The use of an aesthetic coating of noble metals (nickel, gold, silver) causes the element to present itself better,
• Neodymium magnets generate maximum magnetic induction on a contact point, which allows for strong attraction,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the shape) even at a temperature of 230°C or more...
• Due to the ability of free molding and customization to individualized needs, magnetic components can be manufactured in a wide range of shapes and sizes, which expands the range of possible applications,
• Versatile presence in future technologies – they serve a role in data components, electromotive mechanisms, medical devices, also modern systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which makes them useful in miniature devices

Drawbacks and weaknesses of neodymium magnets: tips and applications.

• Brittleness is one of their disadvantages. Upon intense impact they can fracture. We advise keeping them in a strong case, which not only secures 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 strength 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 immune to moisture, in case of application outdoors
• Limited possibility of producing nuts in the magnet and complex forms - recommended is a housing - magnet mounting.
• Possible danger related to microscopic parts of magnets pose a threat, in case of ingestion, which is particularly important in the context of child safety. Additionally, small elements of these devices can disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

The load parameter shown represents the maximum value, recorded under laboratory conditions, meaning:

• with the use of a yoke made of special test steel, ensuring full magnetic saturation
• with a cross-section minimum 10 mm
• with a surface perfectly flat
• under conditions of gap-free contact (surface-to-surface)
• under perpendicular application of breakaway force (90-degree angle)
• in temp. approx. 20°C

Determinants of lifting force in real conditions

It is worth knowing that the working load will differ influenced by elements below, in order of importance:

• Distance – the presence of foreign body (rust, dirt, gap) acts as an insulator, which lowers capacity steeply (even by 50% at 0.5 mm).
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of converting into lifting capacity.
• Material type – the best choice is high-permeability steel. Hardened steels may have worse magnetic properties.
• Surface structure – the smoother and more polished the surface, the better the adhesion and stronger the hold. Unevenness creates an air distance.
• Temperature – heating the magnet causes a temporary drop of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was determined using a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, in contrast under parallel forces the load capacity is reduced by as much as 5 times. In addition, even a slight gap {between} the magnet and the plate lowers the load capacity.