UMGGW 66x8.5 [M8] GW / N38 - magnetic holder rubber internal thread

Advantages and disadvantages of NdFeB magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They have unchanged lifting capacity, and over around 10 years their performance decreases symbolically – ~1% (in testing),
• Neodymium magnets are characterized by highly resistant to loss of magnetic properties caused by external magnetic fields,
• Thanks to the metallic finish, the layer of nickel, gold-plated, or silver-plated gives an clean appearance,
• They show high magnetic induction at the operating surface, making them more effective,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• In view of the ability of free shaping and customization to specialized requirements, magnetic components can be modeled in a wide range of geometric configurations, which increases their versatility,
• Versatile presence in future technologies – they are utilized in HDD drives, brushless drives, advanced medical instruments, and multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which allows their use in compact constructions

Cons of neodymium magnets and proposals for their use:

• To avoid cracks under impact, we recommend using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• Neodymium magnets lose their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation and corrosion.
• Due to limitations in realizing nuts and complicated forms in magnets, we propose using cover - magnetic mount.
• Health risk related to microscopic parts of magnets are risky, when accidentally swallowed, which gains importance in the context of child safety. Additionally, tiny parts of these devices are able to be problematic in diagnostics medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Magnetic strength at its maximum – what affects it?

Magnet power was defined for optimal configuration, including:

• using a sheet made of low-carbon steel, functioning as a circuit closing element
• possessing a massiveness of minimum 10 mm to avoid saturation
• characterized by smoothness
• without any insulating layer between the magnet and steel
• during pulling in a direction perpendicular to the plane
• in stable room temperature

What influences lifting capacity in practice

Effective lifting capacity is affected by specific conditions, including (from priority):

• Gap (between the magnet and the plate), since even a microscopic clearance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to paint, rust or debris).
• Angle of force application – maximum parameter is available only during perpendicular pulling. The force required to slide of the magnet along the surface is usually several times lower (approx. 1/5 of the lifting capacity).
• Steel thickness – insufficiently thick steel causes magnetic saturation, causing part of the power to be escaped into the air.
• Steel grade – the best choice is high-permeability steel. Stainless steels may attract less.
• Base smoothness – the more even the plate, the better the adhesion and stronger the hold. Unevenness creates an air distance.
• Temperature – temperature increase results in weakening of induction. Check the maximum operating temperature for a given model.

* Lifting capacity was assessed using a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Additionally, even a minimal clearance {between} the magnet and the plate decreases the load capacity.