HH 42x8.8 [M6] / N38 - through hole magnetic holder

Advantages as well as disadvantages of rare earth magnets.

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

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (according to literature),
• They are resistant to demagnetization induced by external magnetic fields,
• By applying a decorative layer of nickel, the element gains an aesthetic look,
• The surface of neodymium magnets generates a strong magnetic field – this is a key feature,
• 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...
• Possibility of accurate creating and adapting to individual applications,
• Universal use in modern industrial fields – they serve a role in HDD drives, motor assemblies, precision medical tools, also complex engineering applications.
• 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 steel housing, which not only secures them against impacts but also increases their durability
• Neodymium magnets lose their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We suggest a housing - magnetic holder, due to difficulties in creating nuts inside the magnet and complex forms.
• Potential hazard to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child safety. It is also worth noting that small elements of these products can be problematic in diagnostics medical when they are in the body.
• With budget limitations the cost of neodymium magnets is a challenge,

Detachment force of the magnet in optimal conditions – what it depends on?

The force parameter is a result of laboratory testing conducted under standard conditions:

• using a base made of high-permeability steel, functioning as a ideal flux conductor
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by even structure
• with total lack of distance (no coatings)
• under axial force vector (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

Determinants of lifting force in real conditions

In real-world applications, the real power depends on many variables, ranked from the most important:

• Gap between surfaces – every millimeter of separation (caused e.g. by varnish or dirt) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
• Loading method – declared lifting capacity refers to pulling vertically. When applying parallel force, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Material composition – different alloys attracts identically. Alloy additives weaken the interaction with the magnet.
• Surface condition – smooth surfaces ensure maximum contact, which increases field saturation. Uneven metal reduce efficiency.
• Operating temperature – neodymium magnets have a sensitivity to temperature. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity was determined with the use of a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under parallel forces the load capacity is reduced by as much as 75%. Moreover, even a slight gap {between} the magnet and the plate reduces the load capacity.