UMGW 32x18x8 [M6] GW / N38 - magnetic holder internal thread

Advantages as well as disadvantages of neodymium magnets NdFeB.

In addition to their immense field intensity, neodymium magnets offer the following advantages:

• They retain their magnetic properties for around ten years – the loss is just ~1% (according to analyses),
• They protect against demagnetization induced by external magnetic influence very well,
• Thanks to the glossy finish and gold coating, they have an aesthetic appearance,
• The outer field strength of the magnet shows remarkable magnetic properties,
• They are suitable for high-temperature applications, operating effectively at 230°C+ due to advanced heat resistance and form-specific properties,
• With the option for fine forming and targeted design, these magnets can be produced in various shapes and sizes, greatly improving engineering flexibility,
• Significant impact in new technology industries – they find application in computer drives, electric drives, clinical machines or even high-tech tools,
• Compactness – despite their small size, they provide high effectiveness, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They may fracture when subjected to a powerful impact. If the magnets are exposed to shocks, it is suggested to place them in a metal holder. The steel housing, in the form of a holder, protects the magnet from breakage and enhances its overall resistance,
• Magnets lose magnetic efficiency when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible field weakening (influenced by the magnet’s structure). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Magnets exposed to moisture can degrade. Therefore, for outdoor applications, we suggest waterproof types made of non-metallic composites,
• Limited ability to create precision features in the magnet – the use of a housing is recommended,
• Possible threat from tiny pieces may arise, especially if swallowed, which is notable in the family environments. Moreover, miniature parts from these magnets may hinder health screening after being swallowed,
• Higher purchase price is one of the drawbacks compared to ceramic magnets, especially in budget-sensitive applications

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

The given strength of the magnet means the optimal strength, determined in ideal conditions, specifically:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• with a thickness of minimum 10 mm
• with a smooth surface
• with zero air gap
• with vertical force applied
• at room temperature

Magnet lifting force in use – key factors

In practice, the holding capacity of a magnet is conditioned by these factors, in descending order of importance:

• Air gap between the magnet and the plate, because even a very small distance (e.g. 0.5 mm) causes a drop in lifting force of up to 50%.
• Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
• Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
• Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
• Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
• Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Lifting capacity was determined using a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the lifting capacity is smaller. In addition, even a small distance {between} the magnet and the plate lowers the holding force.