UMGW 36x18x8 [M8] GW / N38 - magnetic holder internal thread

Pros and cons of neodymium magnets.

Apart from their strong power, neodymium magnets have these key benefits:

• They have stable power, and over more than 10 years their performance decreases symbolically – ~1% (according to theory),
• Magnets effectively defend themselves against loss of magnetization caused by foreign field sources,
• In other words, due to the glossy surface of silver, the element is aesthetically pleasing,
• Magnetic induction on the top side of the magnet remains exceptional,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and are able to act (depending on the form) even at a temperature of 230°C or more...
• Possibility of detailed shaping and modifying to complex applications,
• Key role in innovative solutions – they are utilized in mass storage devices, drive modules, advanced medical instruments, also multitasking production systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,

What to avoid - cons of neodymium magnets: application proposals

• To avoid cracks under impact, we recommend using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
• When exposed to high temperature, neodymium magnets experience a drop in force. 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
• They rust in a humid environment - during use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend cover - magnetic mount, due to difficulties in realizing threads inside the magnet and complicated forms.
• Possible danger resulting from small fragments of magnets pose a threat, in case of ingestion, which becomes key in the aspect of protecting the youngest. Furthermore, small elements of these devices can be problematic in diagnostics medical in case of swallowing.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which hinders application in large quantities

Maximum holding power of the magnet – what affects it?

The force parameter is a result of laboratory testing executed under standard conditions:

• using a plate made of high-permeability steel, serving as a ideal flux conductor
• whose transverse dimension is min. 10 mm
• with a plane cleaned and smooth
• with total lack of distance (without paint)
• under perpendicular force vector (90-degree angle)
• in neutral thermal conditions

What influences lifting capacity in practice

Bear in mind that the working load will differ influenced by elements below, in order of importance:

• Space between surfaces – every millimeter of separation (caused e.g. by varnish or dirt) drastically reduces the pulling force, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Steel grade – the best choice is high-permeability steel. Stainless steels may generate lower lifting capacity.
• Plate texture – ground elements ensure maximum contact, which increases force. Uneven metal reduce efficiency.
• Operating temperature – NdFeB sinters have a negative temperature coefficient. When it is hot they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity was measured using a polished steel plate of suitable thickness (min. 20 mm), under perpendicular detachment force, in contrast under shearing force the holding force is lower. In addition, even a small distance {between} the magnet’s surface and the plate reduces the lifting capacity.