UMGZ 48x24x11.5 [M8] GZ / N38 - magnetic holder external thread

Advantages as well as disadvantages of neodymium magnets NdFeB.

Besides their high retention, neodymium magnets are valued for these benefits:

• They retain their attractive force for nearly ten years – the drop is just ~1% (based on simulations),
• They show exceptional resistance to demagnetization from outside magnetic sources,
• By applying a bright layer of silver, the element gains a clean look,
• They possess significant magnetic force measurable at the magnet’s surface,
• These magnets tolerate high temperatures, often exceeding 230°C, when properly designed (in relation to build),
• The ability for precise shaping and adaptation to individual needs – neodymium magnets can be manufactured in a wide range of shapes and sizes, which extends the scope of their use cases,
• Key role in cutting-edge sectors – they are utilized in HDDs, electric motors, diagnostic apparatus or even other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer impressive pulling strength in compact dimensions, which makes them ideal in miniature devices

Disadvantages of neodymium magnets:

• They can break when subjected to a sudden impact. If the magnets are exposed to shocks, they should be placed in a metal holder. The steel housing, in the form of a holder, protects the magnet from fracture and strengthens its overall durability,
• They lose power at extreme temperatures. Most neodymium magnets experience permanent loss in strength when heated above 80°C (depending on the shape and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Due to corrosion risk in humid conditions, it is common to use sealed magnets made of rubber for outdoor use,
• Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing holes directly in the magnet,
• Possible threat linked to microscopic shards may arise, especially if swallowed, which is crucial in the context of child safety. It should also be noted that miniature parts from these devices have the potential to hinder health screening if inside the body,
• In cases of tight budgets, neodymium magnet cost is a challenge,

Maximum magnetic pulling force – what it depends on?

The given strength of the magnet means the optimal strength, measured in ideal conditions, namely:

• with mild steel, used as a magnetic flux conductor
• with a thickness of minimum 10 mm
• with a refined outer layer
• with no separation
• in a perpendicular direction of force
• under standard ambient temperature

What influences lifting capacity in practice

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, since 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 conducted on a smooth plate of suitable thickness, under a perpendicular pulling force, 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 holding force.