NCM 30x13.5x5 / N38 - channel magnetic holder

Strengths as well as weaknesses of neodymium magnets.

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

• They do not lose strength, even during nearly ten years – the decrease in lifting capacity is only ~1% (according to tests),
• Neodymium magnets remain highly resistant to magnetic field loss caused by external field sources,
• Thanks to the metallic finish, the plating of nickel, gold, or silver gives an visually attractive appearance,
• Magnets have maximum magnetic induction on the working surface,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling operation at temperatures approaching 230°C and above...
• Possibility of exact modeling as well as adjusting to specific requirements,
• Key role in electronics industry – they are commonly used in computer drives, brushless drives, precision medical tools, and complex engineering applications.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons of neodymium magnets: application proposals

• To avoid cracks under impact, we suggest using special steel housings. Such a solution secures the magnet and simultaneously increases its durability.
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening 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 extremely resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we advise using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited ability of producing threads in the magnet and complicated shapes - recommended is casing - magnetic holder.
• Possible danger to health – tiny shards of magnets can be dangerous, in case of ingestion, which becomes key in the aspect of protecting the youngest. It is also worth noting that tiny parts of these magnets can complicate diagnosis medical after entering the body.
• Due to expensive raw materials, their price is relatively high,

Optimal lifting capacity of a neodymium magnet – what affects it?

The lifting capacity listed is a theoretical maximum value conducted under standard conditions:

• using a sheet made of low-carbon steel, functioning as a ideal flux conductor
• whose thickness is min. 10 mm
• with an ideally smooth touching surface
• with zero gap (without coatings)
• during pulling in a direction perpendicular to the plane
• at temperature approx. 20 degrees Celsius

Key elements affecting lifting force

In practice, the actual holding force is determined by many variables, presented from most significant:

• Distance (betwixt the magnet and the metal), because even a microscopic distance (e.g. 0.5 mm) results in a reduction in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the maximum value.
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of generating force.
• Material type – the best choice is pure iron steel. Cast iron may generate lower lifting capacity.
• Surface condition – ground elements ensure maximum contact, which improves field saturation. Rough surfaces weaken the grip.
• Thermal environment – temperature increase causes a temporary drop of force. It is worth remembering the thermal limit for a given model.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under perpendicular forces, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet and the plate reduces the load capacity.