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

Strengths and weaknesses of NdFeB magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• They have unchanged lifting capacity, and over more than ten years their performance decreases symbolically – ~1% (in testing),
• Neodymium magnets are exceptionally resistant to demagnetization caused by external magnetic fields,
• The use of an aesthetic finish of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• The surface of neodymium magnets generates a strong magnetic field – this is a distinguishing feature,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Possibility of custom shaping and adjusting to complex applications,
• Versatile presence in advanced technology sectors – they serve a role in mass storage devices, brushless drives, advanced medical instruments, as well as technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which makes them useful in small systems

What to avoid - cons of neodymium magnets and ways of using them

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a strong case, which not only protects them against impacts but also raises their durability
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• We suggest casing - magnetic mount, due to difficulties in producing nuts inside the magnet and complicated forms.
• Potential hazard resulting from small fragments of magnets can be dangerous, if swallowed, which gains importance in the context of child safety. Additionally, small elements of these devices can complicate diagnosis medical in case of swallowing.
• With large orders the cost of neodymium magnets can be a barrier,

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

The force parameter is a theoretical maximum value performed under the following configuration:

• using a plate made of low-carbon steel, functioning as a circuit closing element
• with a cross-section no less than 10 mm
• characterized by lack of roughness
• under conditions of gap-free contact (metal-to-metal)
• for force acting at a right angle (pull-off, not shear)
• at ambient temperature room level

Impact of factors on magnetic holding capacity in practice

Real force is influenced by specific conditions, such as (from priority):

• Clearance – existence of any layer (paint, dirt, gap) acts as an insulator, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Angle of force application – highest force is obtained only during perpendicular pulling. The force required to slide of the magnet along the plate is typically several times lower (approx. 1/5 of the lifting capacity).
• Plate thickness – insufficiently thick plate does not close the flux, causing part of the flux to be wasted into the air.
• Material type – ideal substrate is pure iron steel. Stainless steels may generate lower lifting capacity.
• Surface structure – the more even the surface, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
• Thermal factor – hot environment reduces magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under parallel forces the holding force is lower. Moreover, even a slight gap {between} the magnet and the plate lowers the holding force.