UMGZ 42x20x9 [M8] GZ / N38 - magnetic holder external thread

Strengths and weaknesses of rare earth magnets.

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

• They have constant strength, and over nearly 10 years their attraction force decreases symbolically – ~1% (according to theory),
• Magnets effectively resist against loss of magnetization caused by foreign field sources,
• Thanks to the shiny finish, the layer of nickel, gold-plated, or silver gives an aesthetic appearance,
• Magnetic induction on the top side of the magnet turns out to be extremely intense,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures approaching 230°C and above...
• Possibility of detailed modeling as well as adapting to complex requirements,
• Wide application in innovative solutions – they are utilized in HDD drives, motor assemblies, medical devices, and industrial machines.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of neodymium magnets:

• At very strong impacts they can crack, therefore we advise placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
• When exposed to high temperature, neodymium magnets experience a drop in strength. 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Limited ability of producing nuts in the magnet and complicated shapes - recommended is cover - magnet mounting.
• Potential hazard resulting from small fragments of magnets can be dangerous, if swallowed, which becomes key in the context of child health protection. Additionally, small elements of these devices can be problematic in diagnostics medical when they are in the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Maximum magnetic pulling force – what contributes to it?

The force parameter is a theoretical maximum value executed under standard conditions:

• on a block made of structural steel, effectively closing the magnetic flux
• with a cross-section no less than 10 mm
• characterized by even structure
• with total lack of distance (without paint)
• under vertical force vector (90-degree angle)
• at standard ambient temperature

Practical aspects of lifting capacity – factors

Real force impacted by specific conditions, such as (from most important):

• Distance – existence of foreign body (paint, tape, gap) acts as an insulator, which lowers capacity steeply (even by 50% at 0.5 mm).
• Angle of force application – highest force is obtained only during pulling at a 90° angle. The force required to slide of the magnet along the plate is standardly several times lower (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
• Steel type – mild steel attracts best. Alloy steels lower magnetic properties and holding force.
• Base smoothness – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Roughness creates an air distance.
• Thermal factor – hot environment weakens magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, in contrast under attempts to slide the magnet the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate lowers the load capacity.