UMGGW 34x8 [M4] GW / N38 - magnetic holder rubber internal thread

Advantages and disadvantages of NdFeB magnets.

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

• They do not lose magnetism, even during nearly ten years – the reduction in lifting capacity is only ~1% (based on measurements),
• Neodymium magnets prove to be highly resistant to magnetic field loss caused by external field sources,
• In other words, due to the shiny surface of silver, the element becomes visually attractive,
• Magnets have extremely high magnetic induction on the surface,
• 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 machining as well as adapting to individual requirements,
• Universal use in advanced technology sectors – they serve a role in mass storage devices, brushless drives, diagnostic systems, as well as technologically advanced constructions.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

What to avoid - cons of neodymium magnets: tips and applications.

• Brittleness is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a special holder, which not only secures them against impacts but also increases their 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, as well as 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 possibility of producing threads in the magnet and complicated shapes - preferred is cover - magnetic holder.
• Potential hazard resulting from small fragments of magnets pose a threat, when accidentally swallowed, which gains importance in the context of child health protection. It is also worth noting that tiny parts of these magnets can complicate diagnosis medical when they are in the body.
• Due to expensive raw materials, their price is relatively high,

Best holding force of the magnet in ideal parameters – what it depends on?

The force parameter is a measurement result conducted under standard conditions:

• on a plate made of mild steel, effectively closing the magnetic field
• possessing a massiveness of at least 10 mm to avoid saturation
• with a surface free of scratches
• with direct contact (no impurities)
• for force applied at a right angle (pull-off, not shear)
• in temp. approx. 20°C

Impact of factors on magnetic holding capacity in practice

Holding efficiency impacted by specific conditions, such as (from priority):

• Distance – existence of any layer (rust, tape, gap) acts as an insulator, which reduces power rapidly (even by 50% at 0.5 mm).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Metal thickness – the thinner the sheet, the weaker the hold. Magnetic flux penetrates through instead of converting into lifting capacity.
• Steel grade – ideal substrate is high-permeability steel. Stainless steels may attract less.
• Surface structure – the more even the surface, the better the adhesion and stronger the hold. Unevenness acts like micro-gaps.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was assessed using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, whereas under parallel forces the load capacity is reduced by as much as 5 times. Additionally, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.