MPL 20x20x20 / N38 - lamellar magnet

Pros as well as cons of neodymium magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They do not lose strength, even after nearly 10 years – the drop in lifting capacity is only ~1% (theoretically),
• Magnets perfectly defend themselves against demagnetization caused by external fields,
• The use of an elegant finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Magnets exhibit maximum magnetic induction on the surface,
• Thanks to resistance to high temperature, they are capable of working (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of individual machining as well as adapting to individual requirements,
• Key role in advanced technology sectors – they are utilized in data components, motor assemblies, precision medical tools, also industrial machines.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. 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 experience 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 stable to moisture, when using outdoors
• Limited ability of producing threads in the magnet and complicated forms - recommended is cover - magnet mounting.
• Health risk related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Additionally, small components of these products are able to disrupt the diagnostic process medical after entering the body.
• With mass production the cost of neodymium magnets is economically unviable,

Highest magnetic holding force – what affects it?

Holding force of 31.59 kg is a theoretical maximum value executed under standard conditions:

• with the use of a yoke made of special test steel, guaranteeing maximum field concentration
• with a cross-section no less than 10 mm
• with an ideally smooth contact surface
• with zero gap (without coatings)
• during pulling in a direction vertical to the plane
• in neutral thermal conditions

What influences lifting capacity in practice

Bear in mind that the magnet holding will differ subject to the following factors, in order of importance:

• Air gap (between the magnet and the metal), as even a microscopic distance (e.g. 0.5 mm) leads to a reduction 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 force required to slide of the magnet along the surface is typically several times smaller (approx. 1/5 of the lifting capacity).
• Plate thickness – insufficiently thick sheet does not accept the full field, causing part of the flux to be lost to the other side.
• Chemical composition of the base – low-carbon steel gives the best results. Alloy admixtures reduce magnetic properties and lifting capacity.
• Base smoothness – the more even the plate, the better the adhesion and stronger the hold. Unevenness creates an air distance.
• Thermal factor – hot environment reduces pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under parallel forces the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the lifting capacity.