UMGGZ 22x6 [M4] GZ / N38 - rubber magnetic holder external thread

Strengths as well as weaknesses of neodymium magnets.

Besides their immense field intensity, neodymium magnets offer the following advantages:

• They have constant strength, and over around ten years their attraction force decreases symbolically – ~1% (in testing),
• Neodymium magnets remain remarkably resistant to magnetic field loss caused by magnetic disturbances,
• Thanks to the shimmering finish, the surface of Ni-Cu-Ni, gold, or silver gives an modern appearance,
• Neodymium magnets ensure maximum magnetic induction on a small surface, which increases force concentration,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Possibility of individual shaping and modifying to concrete requirements,
• Significant place in advanced technology sectors – they serve a role in hard drives, motor assemblies, medical devices, as well as multitasking production systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• To avoid cracks under impact, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• Due to limitations in realizing threads and complicated shapes in magnets, we recommend using a housing - magnetic holder.
• Health risk to health – tiny shards 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 elements of these magnets can complicate diagnosis medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Maximum holding power of the magnet – what it depends on?

Information about lifting capacity is the result of a measurement for the most favorable conditions, taking into account:

• with the contact of a yoke made of special test steel, ensuring maximum field concentration
• whose transverse dimension is min. 10 mm
• with an ground contact surface
• without any insulating layer between the magnet and steel
• under axial application of breakaway force (90-degree angle)
• at temperature room level

Lifting capacity in practice – influencing factors

In practice, the actual holding force depends on a number of factors, listed from most significant:

• Clearance – existence of any layer (paint, tape, gap) interrupts the magnetic circuit, which lowers power rapidly (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to pulling vertically. When attempting to slide, the magnet holds significantly lower power (typically approx. 20-30% of maximum force).
• Plate thickness – insufficiently thick steel causes magnetic saturation, causing part of the flux to be wasted into the air.
• Steel grade – the best choice is pure iron steel. Cast iron may have worse magnetic properties.
• Plate texture – smooth surfaces guarantee perfect abutment, which increases field saturation. Rough surfaces reduce efficiency.
• Thermal environment – heating the magnet causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under attempts to slide the magnet the load capacity is reduced by as much as 5 times. Moreover, even a small distance {between} the magnet’s surface and the plate reduces the holding force.