AM lina fi 10 mm - magnetic accessories

Advantages as well as disadvantages of NdFeB magnets.

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

• They have stable power, and over around ten years their attraction force decreases symbolically – ~1% (according to theory),
• Neodymium magnets are highly resistant to loss of magnetic properties caused by magnetic disturbances,
• A magnet with a shiny gold surface has an effective appearance,
• Magnetic induction on the top side of the magnet is extremely intense,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to modularity in forming and the ability to modify to client solutions,
• Universal use in electronics industry – they find application in magnetic memories, electromotive mechanisms, diagnostic systems, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which enables their usage in compact constructions

Disadvantages of NdFeB magnets:

• They are fragile upon heavy impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• When exposed to high temperature, neodymium magnets experience a drop in strength. Often, when the temperature exceeds 80°C, their power 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 recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• Limited ability of making threads in the magnet and complicated shapes - preferred is a housing - magnetic holder.
• Potential hazard resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which is particularly important in the context of child health protection. It is also worth noting that small elements of these products can disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which can limit application in large quantities

Maximum holding power of the magnet – what contributes to it?

The load parameter shown represents the limit force, obtained under ideal test conditions, namely:

• on a base made of structural steel, perfectly concentrating the magnetic field
• with a cross-section minimum 10 mm
• with an polished touching surface
• with zero gap (without impurities)
• under axial force direction (90-degree angle)
• at temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

Please note that the working load will differ influenced by the following factors, in order of importance:

• Air gap (betwixt the magnet and the plate), because even a microscopic clearance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to paint, rust or debris).
• Pull-off angle – note that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Element 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 have worse magnetic properties.
• Smoothness – ideal contact is possible only on smooth steel. Rough texture create air cushions, weakening the magnet.
• Temperature influence – hot environment reduces pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity testing was carried out on a smooth plate of suitable thickness, under a perpendicular pulling force, whereas under shearing force the load capacity is reduced by as much as 5 times. Additionally, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.