UMGW 42x20x9 [M6] GW / N38 - magnetic holder internal thread

Advantages as well as disadvantages of rare earth magnets.

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

• They have constant strength, and over more than ten years their performance decreases symbolically – ~1% (in testing),
• They maintain their magnetic properties even under strong external field,
• By using a lustrous coating of silver, the element presents an modern look,
• Neodymium magnets ensure maximum magnetic induction on a small area, which allows for strong attraction,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to the possibility of flexible molding and adaptation to custom requirements, neodymium magnets can be modeled in a broad palette of shapes and sizes, which amplifies use scope,
• Huge importance in future technologies – they find application in data components, motor assemblies, advanced medical instruments, also technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer high power in compact dimensions, which allows their use in miniature devices

Cons of neodymium magnets: weaknesses and usage proposals

• They are fragile upon heavy impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only protects the magnet but also improves its resistance to damage
• Neodymium magnets lose power when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of strength (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Due to limitations in creating nuts and complex shapes in magnets, we propose using casing - magnetic mount.
• Health risk related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products are able to complicate diagnosis medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what contributes to it?

Information about lifting capacity is the result of a measurement for the most favorable conditions, taking into account:

• using a plate made of high-permeability steel, functioning as a ideal flux conductor
• possessing a thickness of minimum 10 mm to ensure full flux closure
• with a plane cleaned and smooth
• under conditions of ideal adhesion (surface-to-surface)
• for force acting at a right angle (pull-off, not shear)
• in neutral thermal conditions

Determinants of lifting force in real conditions

In practice, the real power depends on several key aspects, presented from the most important:

• Gap between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Load vector – maximum parameter is available only during perpendicular pulling. The resistance to sliding of the magnet along the surface is standardly several times smaller (approx. 1/5 of the lifting capacity).
• Substrate thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Plate material – mild steel attracts best. Higher carbon content reduce magnetic properties and holding force.
• Surface structure – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
• Heat – NdFeB sinters have a sensitivity to temperature. When it is hot they lose power, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was measured using a polished steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, whereas under shearing force the load capacity is reduced by as much as 75%. Additionally, even a minimal clearance {between} the magnet and the plate lowers the holding force.