UMGGZ 66x8.5 [M8] GZ / N38 - rubber magnetic holder external thread

Strengths and weaknesses of NdFeB magnets.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They have constant strength, and over nearly 10 years their attraction force decreases symbolically – ~1% (in testing),
• They are extremely resistant to demagnetization induced by external field influence,
• Thanks to the shiny finish, the plating of nickel, gold, or silver-plated gives an elegant appearance,
• Neodymium magnets generate maximum magnetic induction on a their surface, which ensures high operational effectiveness,
• Thanks to resistance to high temperature, they are able to function (depending on the form) even at temperatures up to 230°C and higher...
• Thanks to the possibility of free forming and adaptation to unique solutions, NdFeB magnets can be produced in a broad palette of geometric configurations, which expands the range of possible applications,
• Huge importance in future technologies – they are utilized in mass storage devices, motor assemblies, diagnostic systems, as well as industrial machines.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

Disadvantages of neodymium magnets:

• At very strong impacts they can break, therefore we advise placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• Limited possibility of producing nuts in the magnet and complicated shapes - preferred is casing - mounting mechanism.
• Potential hazard related to microscopic parts of magnets are risky, when accidentally swallowed, which is particularly important in the context of child safety. It is also worth noting that small elements of these devices are able to complicate diagnosis medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

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

The specified lifting capacity represents the maximum value, obtained under optimal environment, namely:

• with the application of a yoke made of low-carbon steel, guaranteeing maximum field concentration
• with a thickness minimum 10 mm
• with a surface perfectly flat
• with direct contact (without impurities)
• for force acting at a right angle (in the magnet axis)
• in temp. approx. 20°C

Practical lifting capacity: influencing factors

Holding efficiency is affected by specific conditions, including (from most important):

• Air gap (betwixt the magnet and the plate), as even a tiny clearance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Wall thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Metal type – not every steel reacts the same. High carbon content weaken the interaction with the magnet.
• Surface condition – ground elements guarantee perfect abutment, which improves force. Uneven metal weaken the grip.
• Temperature – heating the magnet causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was determined with the use of a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, however under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the holding force.