CM PML-10 / N45 - magnetic gripper

Advantages as well as disadvantages of neodymium magnets.

Besides their tremendous magnetic power, neodymium magnets offer the following advantages:

• Their power is maintained, and after around 10 years it drops only by ~1% (according to research),
• They show high resistance to demagnetization induced by external field influence,
• By applying a lustrous coating of nickel, the element gains an professional look,
• Neodymium magnets deliver maximum magnetic induction on a small area, which increases force concentration,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of precise shaping and adapting to concrete applications,
• Key role in advanced technology sectors – they are commonly used in magnetic memories, drive modules, medical equipment, as well as other advanced devices.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons of neodymium magnets: weaknesses and usage proposals

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• They rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited possibility of creating threads in the magnet and complex shapes - recommended is casing - magnet mounting.
• Health risk to health – tiny shards of magnets are risky, if swallowed, which is particularly important in the context of child safety. Furthermore, small components of these devices can be problematic in diagnostics medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

Best holding force of the magnet in ideal parameters – what it depends on?

The load parameter shown represents the peak performance, recorded under ideal test conditions, specifically:

• on a block made of mild steel, optimally conducting the magnetic field
• whose thickness equals approx. 10 mm
• with a plane free of scratches
• without the slightest insulating layer between the magnet and steel
• under perpendicular force direction (90-degree angle)
• at temperature approx. 20 degrees Celsius

Magnet lifting force in use – key factors

During everyday use, the actual holding force results from a number of factors, ranked from most significant:

• Distance (betwixt the magnet and the plate), since even a very small clearance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to varnish, rust or debris).
• Force direction – remember that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Element thickness – for full efficiency, the steel must be adequately massive. Thin sheet limits the attraction force (the magnet "punches through" it).
• Material composition – not every steel reacts the same. Alloy additives weaken the attraction effect.
• Base smoothness – the smoother and more polished the plate, the better the adhesion and stronger the hold. Unevenness creates an air distance.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, however under parallel forces the holding force is lower. Moreover, even a small distance {between} the magnet and the plate lowers the load capacity.