UMGZ 20x15x7 [M4] GZ / N38 - magnetic holder external thread

Pros as well as cons of rare earth magnets.

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

• They retain attractive force for almost ten years – the drop is just ~1% (according to analyses),
• They show high resistance to demagnetization induced by external disturbances,
• In other words, due to the aesthetic layer of gold, the element is aesthetically pleasing,
• Neodymium magnets achieve maximum magnetic induction on a their surface, which increases force concentration,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and are able to act (depending on the shape) even at a temperature of 230°C or more...
• In view of the possibility of free molding and customization to custom needs, magnetic components can be created in a broad palette of geometric configurations, which makes them more universal,
• Versatile presence in high-tech industry – they serve a role in HDD drives, electromotive mechanisms, medical equipment, and industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which allows their use in miniature devices

Disadvantages of neodymium magnets:

• To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• Neodymium magnets demagnetize 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
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• Due to limitations in producing nuts and complicated forms in magnets, we propose using casing - magnetic holder.
• Possible danger related to microscopic parts of magnets pose a threat, in case of ingestion, which gains importance in the context of child safety. Furthermore, small components of these magnets are able to be problematic in diagnostics medical in case of swallowing.
• With budget limitations the cost of neodymium magnets is a challenge,

Detachment force of the magnet in optimal conditions – what affects it?

Information about lifting capacity was defined for optimal configuration, including:

• using a sheet made of low-carbon steel, functioning as a magnetic yoke
• possessing a thickness of min. 10 mm to ensure full flux closure
• characterized by smoothness
• without the slightest clearance between the magnet and steel
• under perpendicular force direction (90-degree angle)
• in neutral thermal conditions

Determinants of lifting force in real conditions

Please note that the application force may be lower subject to elements below, starting with the most relevant:

• Gap between surfaces – even a fraction of a millimeter of distance (caused e.g. by varnish or dirt) diminishes the pulling force, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to pulling vertically. When applying parallel force, the magnet exhibits much less (typically approx. 20-30% of maximum force).
• Substrate thickness – for full efficiency, the steel must be adequately massive. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Material composition – not every steel reacts the same. High carbon content worsen the interaction with the magnet.
• Surface quality – the smoother and more polished the surface, the better the adhesion and stronger the hold. Roughness creates an air distance.
• Temperature influence – high temperature weakens magnetic field. Exceeding the limit temperature can permanently damage the magnet.

* Holding force was measured on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the load capacity.