UMGW 48x24x11.5 [M8] GW / N38 - magnetic holder internal thread

Strengths as well as weaknesses of NdFeB magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They have constant strength, and over more than ten years their performance decreases symbolically – ~1% (according to theory),
• Neodymium magnets are characterized by remarkably resistant to loss of magnetic properties caused by external magnetic fields,
• The use of an refined finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• Magnets are distinguished by extremely high magnetic induction on the surface,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Possibility of exact creating as well as modifying to specific conditions,
• Universal use in electronics industry – they serve a role in magnetic memories, electric drive systems, precision medical tools, also industrial machines.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Disadvantages of NdFeB magnets:

• They are fragile upon heavy impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in force. 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
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing threads and complicated shapes in magnets, we propose using cover - magnetic mount.
• Potential hazard resulting from small fragments of magnets can be dangerous, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Additionally, small components of these devices can complicate diagnosis medical in case of swallowing.
• Due to complex production process, their price exceeds standard values,

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

Magnet power is the result of a measurement for the most favorable conditions, taking into account:

• using a sheet made of mild steel, acting as a ideal flux conductor
• whose transverse dimension is min. 10 mm
• with an ideally smooth contact surface
• with total lack of distance (no coatings)
• during detachment in a direction vertical to the plane
• at conditions approx. 20°C

What influences lifting capacity in practice

Effective lifting capacity impacted by specific conditions, mainly (from most important):

• Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or unevenness) drastically reduces the pulling force, often by half at just 0.5 mm.
• Direction of force – maximum parameter is reached only during perpendicular pulling. The force required to slide of the magnet along the surface is standardly many times lower (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be adequately massive. Thin sheet limits the attraction force (the magnet "punches through" it).
• Material type – the best choice is pure iron steel. Stainless steels may generate lower lifting capacity.
• Surface condition – ground elements guarantee perfect abutment, which improves field saturation. Uneven metal weaken the grip.
• Operating temperature – NdFeB sinters have a negative temperature coefficient. When it is hot they are weaker, and in frost gain strength (up to a certain limit).

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, however under parallel forces the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the load capacity.