MW 10x10 / N38 - cylindrical magnet

Advantages as well as disadvantages of neodymium magnets.

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

• They retain magnetic properties for nearly ten years – the loss is just ~1% (according to analyses),
• Magnets effectively resist against loss of magnetization caused by external fields,
• The use of an shiny finish of noble metals (nickel, gold, silver) causes the element to look better,
• Magnets possess very high magnetic induction on the outer side,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures reaching 230°C and above...
• Possibility of detailed forming as well as adjusting to specific requirements,
• Significant place in electronics industry – they are utilized in data components, electric drive systems, precision medical tools, and technologically advanced constructions.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets and ways of using them

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation and corrosion.
• Due to limitations in producing nuts and complicated shapes in magnets, we recommend using a housing - magnetic mechanism.
• Health risk to health – tiny shards of magnets pose a threat, in case of ingestion, which gains importance in the context of child health protection. Furthermore, tiny parts of these devices are able to complicate diagnosis medical when they are in the body.
• Due to neodymium price, their price exceeds standard values,

Maximum holding power of the magnet – what contributes to it?

Breakaway force is the result of a measurement for the most favorable conditions, including:

• using a plate made of high-permeability steel, acting as a circuit closing element
• possessing a thickness of min. 10 mm to ensure full flux closure
• with an polished contact surface
• without any clearance between the magnet and steel
• under perpendicular application of breakaway force (90-degree angle)
• in temp. approx. 20°C

Practical lifting capacity: influencing factors

Please note that the application force may be lower depending on elements below, starting with the most relevant:

• Distance – the presence of any layer (rust, tape, gap) acts as an insulator, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is reached only during perpendicular pulling. The shear force of the magnet along the surface is typically many times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – insufficiently thick sheet causes magnetic saturation, causing part of the power to be lost to the other side.
• Steel grade – ideal substrate is pure iron steel. Hardened steels may generate lower lifting capacity.
• Base smoothness – the smoother and more polished the surface, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Thermal environment – temperature increase results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was tested on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the load capacity is reduced by as much as fivefold. In addition, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.