UMGGW 29x8 [M4] GW / N38 - magnetic holder rubber internal thread

Advantages and disadvantages of neodymium magnets NdFeB.

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

• Their magnetic field is durable, and after approximately ten years, it drops only by ~1% (according to research),
• They remain magnetized despite exposure to strong external fields,
• Because of the lustrous layer of gold, the component looks visually appealing,
• They exhibit extremely high levels of magnetic induction near the outer area of the magnet,
• Neodymium magnets are known for strong magnetic induction and the ability to work at temperatures up to 230°C or higher (depending on the shape),
• With the option for fine forming and precise design, these magnets can be produced in multiple shapes and sizes, greatly improving application potential,
• Wide application in advanced technical fields – they are used in data storage devices, electromechanical systems, medical equipment or even high-tech tools,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in tiny dimensions, which makes them ideal in small systems

Disadvantages of magnetic elements:

• They may fracture when subjected to a powerful impact. If the magnets are exposed to physical collisions, they should be placed in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage , and at the same time enhances its overall durability,
• High temperatures may significantly reduce the strength of neodymium magnets. Typically, above 80°C, they experience permanent decline in performance (depending on shape). To prevent this, we offer heat-resistant magnets marked [AH], capable of working up to 230°C, which makes them perfect for high-temperature use,
• Magnets exposed to moisture can degrade. Therefore, for outdoor applications, it's best to use waterproof types made of coated materials,
• Using a cover – such as a magnetic holder – is advised due to the limitations in manufacturing fine shapes directly in the magnet,
• Possible threat related to magnet particles may arise, if ingested accidentally, which is crucial in the family environments. It should also be noted that minuscule fragments from these magnets can interfere with diagnostics when ingested,
• High unit cost – neodymium magnets are costlier than other types of magnets (e.g., ferrite), which can restrict large-scale applications

Magnetic strength at its maximum – what contributes to it?

The given pulling force of the magnet corresponds to the maximum force, determined in a perfect environment, specifically:

• with the use of low-carbon steel plate serving as a magnetic yoke
• of a thickness of at least 10 mm
• with a polished side
• with no separation
• under perpendicular detachment force
• in normal thermal conditions

Practical aspects of lifting capacity – factors

Practical lifting force is dependent on elements, by priority:

• Air gap between the magnet and the plate, as 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 assessed with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, however under shearing force the load capacity is reduced by as much as fivefold. In addition, even a minimal clearance {between} the magnet and the plate decreases the load capacity.