UMGW 36x18x8 [M8] GW / N38 - magnetic holder internal thread

Advantages as well as disadvantages of neodymium magnets NdFeB.

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

• They virtually do not lose power, because even after 10 years, the performance loss is only ~1% (according to literature),
• They protect against demagnetization induced by ambient magnetic influence effectively,
• The use of a polished silver surface provides a eye-catching finish,
• They exhibit extremely high levels of magnetic induction near the outer area of the magnet,
• Thanks to their high temperature resistance, they can operate (depending on the geometry) even at temperatures up to 230°C or more,
• With the option for tailored forming and targeted design, these magnets can be produced in numerous shapes and sizes, greatly improving application potential,
• Key role in advanced technical fields – they serve a purpose in data storage devices, electric drives, healthcare devices and high-tech tools,
• Thanks to their efficiency per volume, small magnets offer high magnetic performance, in miniature format,

Disadvantages of neodymium magnets:

• They can break when subjected to a powerful impact. If the magnets are exposed to physical collisions, it is advisable to use in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage and additionally strengthens 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 height). 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,
• Due to corrosion risk in humid conditions, it is wise to use sealed magnets made of protective material for outdoor use,
• Using a cover – such as a magnetic holder – is advised due to the restrictions in manufacturing complex structures directly in the magnet,
• Possible threat from tiny pieces may arise, when consumed by mistake, which is significant in the context of child safety. Additionally, small elements from these products may interfere with diagnostics if inside the body,
• Due to the price of neodymium, their cost is relatively high,

Maximum magnetic pulling force – what affects it?

The given pulling force of the magnet corresponds to the maximum force, assessed in the best circumstances, specifically:

• with the use of low-carbon steel plate serving as a magnetic yoke
• having a thickness of no less than 10 millimeters
• with a refined outer layer
• with no separation
• in a perpendicular direction of force
• under standard ambient temperature

Determinants of lifting force in real conditions

Practical lifting force is dependent on factors, listed from the most critical to the less significant:

• Air gap between the magnet and the plate, because even a very small distance (e.g. 0.5 mm) can cause 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 with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular detachment force, whereas under parallel forces the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet’s surface and the plate decreases the holding force.