AM klisza magnetyczna 50 x 50 mm - magnetic accessories

Advantages and disadvantages of rare earth magnets.

Besides their tremendous magnetic power, neodymium magnets offer the following advantages:

• They retain attractive force for around ten years – the drop is just ~1% (in theory),
• Magnets very well resist against demagnetization caused by external fields,
• In other words, due to the metallic finish of silver, the element looks attractive,
• Magnetic induction on the surface of the magnet turns out to be exceptional,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for functioning at temperatures approaching 230°C and above...
• Possibility of accurate forming as well as optimizing to concrete conditions,
• Fundamental importance in future technologies – they find application in hard drives, electric drive systems, diagnostic systems, and multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which makes them useful in compact constructions

Disadvantages of neodymium magnets:

• At strong impacts they can crack, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and 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, 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 stable to moisture, in case of application outdoors
• Limited ability of producing nuts in the magnet and complicated shapes - preferred is casing - magnet mounting.
• Health risk resulting from small fragments of magnets can be dangerous, if swallowed, which gains importance in the context of child health protection. Additionally, small components of these devices are able to complicate diagnosis medical after entering the body.
• Due to neodymium price, their price is higher than average,

Maximum lifting force for a neodymium magnet – what contributes to it?

Holding force of 0 kg is a theoretical maximum value performed under the following configuration:

• on a base made of mild steel, effectively closing the magnetic field
• with a cross-section of at least 10 mm
• characterized by even structure
• under conditions of gap-free contact (surface-to-surface)
• during detachment in a direction perpendicular to the plane
• at temperature room level

Practical aspects of lifting capacity – factors

Real force is influenced by specific conditions, mainly (from priority):

• Gap (betwixt the magnet and the metal), because even a microscopic clearance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to varnish, rust or debris).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Steel grade – the best choice is pure iron steel. Stainless steels may attract less.
• Surface condition – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces reduce efficiency.
• Temperature – heating the magnet causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under parallel forces the holding force is lower. In addition, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.