AM lina fi 10 mm - magnetic accessories

Advantages as well as disadvantages of neodymium magnets.

Besides their tremendous field intensity, neodymium magnets offer the following advantages:

• Their power is durable, and after approximately ten years it decreases only by ~1% (according to research),
• They possess excellent resistance to magnetism drop as a result of external fields,
• The use of an shiny coating of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Magnets are characterized by very high magnetic induction on the surface,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, allowing for action at temperatures reaching 230°C and above...
• Thanks to flexibility in forming and the capacity to modify to complex applications,
• Key role in future technologies – they are used in computer drives, electric motors, precision medical tools, as well as multitasking production systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets and proposals for their use:

• They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets lose strength when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Limited ability of producing threads in the magnet and complicated forms - recommended is cover - mounting mechanism.
• Possible danger related to microscopic parts of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child health protection. It is also worth noting that small components of these devices are able to be problematic in diagnostics medical when they are in the body.
• Due to complex production process, their price is relatively high,

Maximum magnetic pulling force – what contributes to it?

Breakaway force was defined for optimal configuration, assuming:

• using a sheet made of low-carbon steel, functioning as a magnetic yoke
• possessing a massiveness of min. 10 mm to avoid saturation
• with a surface perfectly flat
• without any air gap between the magnet and steel
• under vertical force vector (90-degree angle)
• at conditions approx. 20°C

Determinants of practical lifting force of a magnet

It is worth knowing that the magnet holding may be lower influenced by elements below, starting with the most relevant:

• Distance (between the magnet and the metal), as even a tiny clearance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to varnish, rust or dirt).
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Steel thickness – insufficiently thick steel does not close the flux, causing part of the flux to be escaped into the air.
• Plate material – mild steel attracts best. Alloy admixtures lower magnetic properties and lifting capacity.
• Plate texture – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces weaken the grip.
• Thermal conditions – neodymium magnets have a negative temperature coefficient. At higher temperatures they lose power, and in frost they can be stronger (up to a certain limit).

* Lifting capacity testing was conducted on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, whereas under attempts to slide the magnet the load capacity is reduced by as much as 75%. In addition, even a small distance {between} the magnet and the plate reduces the load capacity.