UMGGZ 88x8.5 [M8] GZ / N38 - rubber magnetic holder external thread

Advantages and disadvantages of rare earth magnets.

Apart from their consistent magnetic energy, neodymium magnets have these key benefits:

• They virtually do not lose strength, because even after ten years the decline in efficiency is only ~1% (in laboratory conditions),
• They have excellent resistance to weakening of magnetic properties when exposed to external fields,
• A magnet with a smooth gold surface has an effective appearance,
• Magnetic induction on the top side of the magnet is exceptional,
• Thanks to resistance to high temperature, they are capable of working (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of exact creating as well as adjusting to specific needs,
• Significant place in innovative solutions – they are utilized in computer drives, brushless drives, precision medical tools, and industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer high power in tiny dimensions, which allows their use in small systems

Cons of neodymium magnets: weaknesses and usage proposals

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in special housings. 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 power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
• We recommend cover - magnetic mount, due to difficulties in realizing threads inside the magnet and complex shapes.
• Possible danger resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, tiny parts of these products can be problematic in diagnostics medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum lifting force for a neodymium magnet – what it depends on?

The declared magnet strength refers to the maximum value, measured under optimal environment, specifically:

• with the use of a yoke made of low-carbon steel, ensuring full magnetic saturation
• with a thickness minimum 10 mm
• characterized by even structure
• under conditions of no distance (surface-to-surface)
• during pulling in a direction vertical to the mounting surface
• at temperature room level

Magnet lifting force in use – key factors

Bear in mind that the application force will differ subject to elements below, starting with the most relevant:

• Gap between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Loading method – catalog parameter refers to pulling vertically. When attempting to slide, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Material composition – different alloys reacts the same. High carbon content weaken the interaction with the magnet.
• Surface structure – the smoother and more polished the surface, the larger the contact zone and stronger the hold. Unevenness creates an air distance.
• Heat – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and in frost gain strength (up to a certain limit).

* Lifting capacity was measured using a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the load capacity is reduced by as much as 5 times. Moreover, even a slight gap {between} the magnet’s surface and the plate reduces the holding force.