UMS 16x6.5x3.5x5 / N38 - conical magnetic holder

Pros and cons of NdFeB magnets.

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

• They retain attractive force for around ten years – the drop is just ~1% (based on simulations),
• They possess excellent resistance to magnetic field loss when exposed to opposing magnetic fields,
• In other words, due to the reflective finish of nickel, the element gains a professional look,
• Magnets have exceptionally strong magnetic induction on the outer side,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to modularity in designing and the ability to customize to individual projects,
• Fundamental importance in modern technologies – they serve a role in HDD drives, electric drive systems, medical devices, and other advanced devices.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets and proposals for their use:

• To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop 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 very resistant to heat
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• We recommend cover - magnetic holder, due to difficulties in creating nuts inside the magnet and complex forms.
• Health risk related to microscopic parts of magnets are risky, in case of ingestion, which becomes key in the context of child safety. It is also worth noting that tiny parts of these products can complicate diagnosis medical after entering the body.
• Due to neodymium price, their price is higher than average,

Breakaway strength of the magnet in ideal conditions – what affects it?

Holding force of 5 kg is a theoretical maximum value executed under standard conditions:

• on a block made of structural steel, perfectly concentrating the magnetic flux
• possessing a massiveness of min. 10 mm to avoid saturation
• with a surface free of scratches
• without the slightest air gap between the magnet and steel
• during detachment in a direction vertical to the plane
• in stable room temperature

Impact of factors on magnetic holding capacity in practice

In real-world applications, the actual lifting capacity results from many variables, ranked from crucial:

• Distance – existence of foreign body (paint, dirt, air) acts as an insulator, which lowers power steeply (even by 50% at 0.5 mm).
• Force direction – note that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Element thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Material composition – not every steel attracts identically. High carbon content worsen the attraction effect.
• Surface structure – the smoother and more polished the surface, the better the adhesion and stronger the hold. Roughness 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 was determined with the use of a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, whereas under shearing force the holding force is lower. Moreover, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.