UMGZ 75x34x18 [M10] GZ / N38 - magnetic holder external thread

Advantages and disadvantages of rare earth magnets.

Apart from their strong holding force, neodymium magnets have these key benefits:

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (according to literature),
• Magnets very well protect themselves against demagnetization caused by external fields,
• A magnet with a shiny gold surface has better aesthetics,
• Magnetic induction on the working layer of the magnet is exceptional,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of individual machining as well as adjusting to individual conditions,
• Universal use in future technologies – they are used in HDD drives, electromotive mechanisms, medical equipment, also modern systems.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which allows their use in compact constructions

Disadvantages of NdFeB magnets:

• At very strong impacts they can crack, therefore we advise placing them in special holders. A metal housing provides additional protection against damage and increases the magnet's durability.
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• Due to limitations in producing nuts and complicated forms in magnets, we propose using a housing - magnetic mount.
• Possible danger related to microscopic parts of magnets pose a threat, in case of ingestion, which becomes key in the aspect of protecting the youngest. It is also worth noting that small components of these magnets are able to disrupt the diagnostic process medical in case of swallowing.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which hinders application in large quantities

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

The specified lifting capacity represents the limit force, recorded under optimal environment, namely:

• on a plate made of structural steel, optimally conducting the magnetic field
• with a cross-section no less than 10 mm
• characterized by lack of roughness
• with zero gap (without paint)
• for force acting at a right angle (in the magnet axis)
• at temperature approx. 20 degrees Celsius

Determinants of lifting force in real conditions

It is worth knowing that the application force will differ depending on the following factors, in order of importance:

• Distance (betwixt the magnet and the metal), as even a very small distance (e.g. 0.5 mm) leads to a reduction in force by up to 50% (this also applies to paint, corrosion or dirt).
• Load vector – maximum parameter is available only during perpendicular pulling. The resistance to sliding of the magnet along the surface is typically many times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of converting into lifting capacity.
• Metal type – not every steel attracts identically. Alloy additives worsen the interaction with the magnet.
• Surface finish – ideal contact is possible only on polished steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal environment – heating the magnet results in weakening of induction. Check the thermal limit for a given model.

* Lifting capacity testing was performed on a smooth plate of suitable thickness, under a perpendicular pulling force, whereas under shearing force the load capacity is reduced by as much as 5 times. Additionally, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.