UMGZ 42x20x9 [M8] GZ / N38 - magnetic holder external thread

Pros as well as cons of rare earth magnets.

Apart from their strong power, neodymium magnets have these key benefits:

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (based on calculations),
• Neodymium magnets are characterized by exceptionally resistant to magnetic field loss caused by external interference,
• In other words, due to the shiny surface of nickel, the element gains a professional look,
• They feature high magnetic induction at the operating surface, which improves attraction properties,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to the ability of free forming and adaptation to unique projects, NdFeB magnets can be manufactured in a broad palette of geometric configurations, which expands the range of possible applications,
• Key role in modern technologies – they serve a role in hard drives, brushless drives, medical equipment, as well as technologically advanced constructions.
• Thanks to their power density, small magnets offer high operating force, in miniature format,

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• Limited ability of making threads in the magnet and complex shapes - recommended is a housing - magnetic holder.
• Potential hazard resulting from small fragments of magnets pose a threat, in case of ingestion, which gains importance in the context of child health protection. Additionally, small elements of these devices are able to complicate diagnosis medical in case of swallowing.
• Due to expensive raw materials, their price is higher than average,

Highest magnetic holding force – what it depends on?

The load parameter shown represents the peak performance, measured under laboratory conditions, specifically:

• on a plate made of structural steel, effectively closing the magnetic field
• with a cross-section of at least 10 mm
• characterized by lack of roughness
• under conditions of no distance (metal-to-metal)
• under axial force vector (90-degree angle)
• in temp. approx. 20°C

Magnet lifting force in use – key factors

In real-world applications, the actual lifting capacity is determined by several key aspects, listed from most significant:

• Air gap (between the magnet and the plate), as even a microscopic clearance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to paint, rust or dirt).
• Force direction – remember that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops significantly, often to levels of 20-30% of the nominal value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of generating force.
• Metal type – different alloys reacts the same. High carbon content worsen the attraction effect.
• Surface finish – full contact is possible only on polished steel. Rough texture create air cushions, weakening the magnet.
• Thermal conditions – 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 assessed by applying a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular pulling force, whereas under shearing force the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the load capacity.