UMGGZ 22x6 [M4] GZ / N38 - rubber magnetic holder external thread

Strengths as well as weaknesses of rare earth magnets.

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

• They do not lose power, even after nearly ten years – the drop in lifting capacity is only ~1% (based on measurements),
• They have excellent resistance to magnetic field loss as a result of opposing magnetic fields,
• The use of an refined coating of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Neodymium magnets generate maximum magnetic induction on a small area, which allows for strong attraction,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of precise creating and adapting to precise requirements,
• Versatile presence in electronics industry – they find application in hard drives, electric drive systems, medical devices, as well as technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only protects the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in strength. 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
• They rust in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We recommend cover - magnetic mount, due to difficulties in realizing threads inside the magnet and complex forms.
• Potential hazard to health – tiny shards of magnets are risky, in case of ingestion, which becomes key in the aspect of protecting the youngest. It is also worth noting that tiny parts of these magnets are able to be problematic in diagnostics medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which hinders application in large quantities

Best holding force of the magnet in ideal parameters – what affects it?

The declared magnet strength represents the peak performance, measured under ideal test conditions, namely:

• on a base made of mild steel, perfectly concentrating the magnetic field
• whose thickness equals approx. 10 mm
• with a plane cleaned and smooth
• under conditions of no distance (metal-to-metal)
• during pulling in a direction perpendicular to the mounting surface
• in temp. approx. 20°C

Lifting capacity in practice – influencing factors

It is worth knowing that the application force will differ depending on the following factors, starting with the most relevant:

• Space between magnet and steel – every millimeter of separation (caused e.g. by varnish or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – highest force is available only during pulling at a 90° angle. The force required to slide of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Steel type – mild steel attracts best. Alloy admixtures decrease magnetic properties and lifting capacity.
• Smoothness – ideal contact is possible only on polished steel. Rough texture reduce the real contact area, reducing force.
• Operating temperature – NdFeB sinters have a sensitivity to temperature. When it is hot they are weaker, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was conducted on a smooth plate of optimal thickness, under a perpendicular pulling force, whereas under attempts to slide the magnet the lifting capacity is smaller. In addition, even a small distance {between} the magnet’s surface and the plate reduces the load capacity.