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

Advantages as well as disadvantages of neodymium magnets NdFeB.

Besides their durability, neodymium magnets are valued for these benefits:

• Their power is maintained, and after around 10 years, it drops only by ~1% (according to research),
• They remain magnetized despite exposure to magnetic surroundings,
• In other words, due to the metallic gold coating, the magnet obtains an stylish appearance,
• They have exceptional magnetic induction on the surface of the magnet,
• Thanks to their enhanced temperature resistance, they can operate (depending on the geometry) even at temperatures up to 230°C or more,
• With the option for customized forming and precise design, these magnets can be produced in various shapes and sizes, greatly improving application potential,
• Important function in new technology industries – they are used in computer drives, rotating machines, medical equipment as well as sophisticated instruments,
• 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 neodymium magnets:

• They can break when subjected to a heavy impact. If the magnets are exposed to external force, it is advisable to use in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage while also strengthens its overall robustness,
• Magnets lose magnetic efficiency when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible magnetic decay (influenced by the magnet’s form). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• They rust in a wet environment. If exposed to rain, we recommend using moisture-resistant magnets, such as those made of rubber,
• Limited ability to create internal holes in the magnet – the use of a external casing is recommended,
• Possible threat linked to microscopic shards may arise, in case of ingestion, which is important in the protection of children. Furthermore, small elements from these assemblies may complicate medical imaging once in the system,
• Due to expensive raw materials, their cost is relatively high,

Maximum lifting force for a neodymium magnet – what it depends on?

The given lifting capacity of the magnet represents the maximum lifting force, measured in the best circumstances, that is:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a polished side
• in conditions of no clearance
• in a perpendicular direction of force
• under standard ambient temperature

Practical lifting capacity: influencing factors

In practice, the holding capacity of a magnet is affected by the following aspects, from crucial to less important:

• Air gap between the magnet and the plate, as 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 testing was carried out on a smooth plate of suitable thickness, under perpendicular forces, however under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the load capacity.