UMGGZ 88x8.5 [M8] GZ / N38 - rubber magnetic holder external thread

Pros and cons of neodymium magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They have stable power, and over nearly 10 years their performance decreases symbolically – ~1% (according to theory),
• Magnets perfectly protect themselves against loss of magnetization caused by foreign field sources,
• Thanks to the shimmering finish, the layer of Ni-Cu-Ni, gold, or silver-plated gives an elegant appearance,
• They feature high magnetic induction at the operating surface, which increases their power,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of individual machining and modifying to precise needs,
• Key role in electronics industry – they are commonly used in magnetic memories, electromotive mechanisms, diagnostic systems, also other advanced devices.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• At very strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets lose their force 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
• They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• We recommend a housing - magnetic holder, due to difficulties in producing threads inside the magnet and complex forms.
• Potential hazard resulting from small fragments of magnets can be dangerous, in case of ingestion, which gains importance in the aspect of protecting the youngest. Furthermore, small components of these devices can be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Optimal lifting capacity of a neodymium magnet – what it depends on?

The lifting capacity listed is a result of laboratory testing performed under standard conditions:

• with the application of a yoke made of low-carbon steel, guaranteeing maximum field concentration
• whose transverse dimension equals approx. 10 mm
• with a plane perfectly flat
• without the slightest insulating layer between the magnet and steel
• for force acting at a right angle (in the magnet axis)
• at ambient temperature room level

Determinants of lifting force in real conditions

Bear in mind that the application force will differ subject to elements below, starting with the most relevant:

• Clearance – existence of foreign body (rust, dirt, air) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Force direction – declared lifting capacity refers to pulling vertically. When applying parallel force, the magnet exhibits significantly lower power (often approx. 20-30% of nominal force).
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Material composition – different alloys attracts identically. High carbon content worsen the attraction effect.
• Surface finish – ideal contact is obtained only on smooth steel. Any scratches and bumps reduce the real contact area, reducing force.
• Temperature influence – high temperature weakens magnetic field. Too high temperature can permanently damage the magnet.

* Holding force was tested on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under shearing force the load capacity is reduced by as much as 5 times. In addition, even a minimal clearance {between} the magnet’s surface and the plate lowers the holding force.