UMGW 25x17x8 [M5] GW / N38 - magnetic holder internal thread

Pros and cons of NdFeB magnets.

Besides their immense magnetic power, neodymium magnets offer the following advantages:

• They have stable power, and over nearly 10 years their performance decreases symbolically – ~1% (according to theory),
• Neodymium magnets are characterized by remarkably resistant to demagnetization caused by magnetic disturbances,
• The use of an elegant layer of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Magnets possess maximum magnetic induction on the outer side,
• 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...
• Considering the potential of accurate shaping and customization to custom solutions, neodymium magnets can be created in a variety of shapes and sizes, which increases their versatility,
• Huge importance in innovative solutions – they are utilized in mass storage devices, drive modules, medical devices, as well as modern systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only shields the magnet but also improves its resistance to damage
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we advise using waterproof magnets made of rubber, plastic or other material resistant to moisture
• Due to limitations in creating threads and complicated forms in magnets, we recommend using cover - magnetic mechanism.
• Potential hazard resulting from small fragments of magnets pose a threat, when accidentally swallowed, which is particularly important 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.
• Due to complex production process, their price is higher than average,

Highest magnetic holding force – what contributes to it?

Magnet power was determined for ideal contact conditions, including:

• with the contact of a sheet made of special test steel, guaranteeing full magnetic saturation
• possessing a massiveness of min. 10 mm to avoid saturation
• characterized by lack of roughness
• without any air gap between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• in neutral thermal conditions

Magnet lifting force in use – key factors

Holding efficiency is affected by working environment parameters, including (from most important):

• Space between magnet and steel – every millimeter of separation (caused e.g. by varnish or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Load vector – highest force is reached only during perpendicular pulling. The resistance to sliding of the magnet along the plate is standardly many times smaller (approx. 1/5 of the lifting capacity).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of generating force.
• Steel type – mild steel attracts best. Alloy admixtures decrease magnetic properties and lifting capacity.
• Surface quality – the more even the surface, the larger the contact zone and stronger the hold. Roughness acts like micro-gaps.
• Operating temperature – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and in frost they can be stronger (up to a certain limit).

* Holding force was measured on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the holding force is lower. Additionally, even a small distance {between} the magnet and the plate reduces the holding force.