NC NeoCube fi 5 mm kuleczki kolorowe / N38 - neocube

Pros and cons of rare earth magnets.

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

• They do not lose magnetism, even during approximately 10 years – the drop in strength is only ~1% (theoretically),
• They do not lose their magnetic properties even under strong external field,
• In other words, due to the shiny finish of gold, the element looks attractive,
• They are known for high magnetic induction at the operating surface, which affects their effectiveness,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Possibility of precise shaping and optimizing to precise applications,
• Universal use in modern industrial fields – they are used in hard drives, brushless drives, diagnostic systems, also technologically advanced constructions.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• Neodymium magnets decrease their power 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 durability even at temperatures up to 230°C
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Limited ability of creating nuts in the magnet and complicated forms - preferred is cover - magnet mounting.
• Possible danger resulting from small fragments of magnets are risky, when accidentally swallowed, which becomes key in the context of child health protection. Furthermore, small elements of these products can disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which hinders application in large quantities

Maximum lifting capacity of the magnet – what it depends on?

Magnet power was determined for the most favorable conditions, assuming:

• using a sheet made of high-permeability steel, serving as a magnetic yoke
• possessing a thickness of at least 10 mm to ensure full flux closure
• with an ground touching surface
• without the slightest clearance between the magnet and steel
• for force applied at a right angle (pull-off, not shear)
• at temperature room level

Determinants of practical lifting force of a magnet

It is worth knowing that the application force may be lower depending on the following factors, starting with the most relevant:

• Distance – the presence of any layer (rust, dirt, air) interrupts the magnetic circuit, which reduces capacity steeply (even by 50% at 0.5 mm).
• Force direction – remember that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Steel grade – the best choice is high-permeability steel. Hardened steels may have worse magnetic properties.
• Surface finish – full contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Temperature – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity was assessed by applying a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, however under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a minimal clearance {between} the magnet and the plate lowers the load capacity.