MP 62x42x25 / N38 - ring magnet

Pros and cons of rare earth magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (in laboratory conditions),
• Neodymium magnets are characterized by remarkably resistant to demagnetization caused by external field sources,
• By covering with a shiny layer of nickel, the element presents an modern look,
• Neodymium magnets deliver maximum magnetic induction on a small surface, which allows for strong attraction,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Possibility of accurate machining and optimizing to concrete requirements,
• Versatile presence in high-tech industry – they serve a role in computer drives, brushless drives, medical devices, as well as complex engineering applications.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Cons 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 raises their durability
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited ability of creating threads in the magnet and complicated forms - preferred is casing - magnet mounting.
• Possible danger related to microscopic parts of magnets can be dangerous, if swallowed, which becomes key in the context of child health protection. Furthermore, tiny parts of these products can disrupt the diagnostic process medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Highest magnetic holding force – what affects it?

Holding force of 58.67 kg is a result of laboratory testing executed under specific, ideal conditions:

• using a plate made of low-carbon steel, serving as a ideal flux conductor
• with a thickness no less than 10 mm
• with a plane cleaned and smooth
• under conditions of ideal adhesion (surface-to-surface)
• during detachment in a direction vertical to the plane
• at standard ambient temperature

Practical lifting capacity: influencing factors

In practice, the real power depends on several key aspects, ranked from most significant:

• Distance (betwixt the magnet and the metal), since even a microscopic clearance (e.g. 0.5 mm) can cause a decrease in force by up to 50% (this also applies to varnish, corrosion or debris).
• Force direction – note that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
• Material type – the best choice is pure iron steel. Hardened steels may attract less.
• Surface quality – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Unevenness creates an air distance.
• Thermal environment – temperature increase causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity testing was carried out on plates with a smooth surface of suitable thickness, under perpendicular forces, whereas under parallel forces the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet’s surface and the plate reduces the holding force.