NCM 10x13.5x5 / N38 - channel magnetic holder

Strengths as well as weaknesses of NdFeB magnets.

Apart from their strong magnetism, neodymium magnets have these key benefits:

• They virtually do not lose strength, because even after ten years the performance loss is only ~1% (according to literature),
• They retain their magnetic properties even under close interference source,
• The use of an refined finish of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Magnetic induction on the surface of the magnet remains impressive,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for action at temperatures approaching 230°C and above...
• Thanks to flexibility in constructing and the capacity to modify to client solutions,
• Key role in future technologies – they find application in magnetic memories, drive modules, advanced medical instruments, also industrial machines.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They are fragile upon heavy impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only protects the magnet but also increases its resistance to damage
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (a factor is the shape and 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 rust. Therefore during using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Limited possibility of producing threads in the magnet and complex shapes - recommended is cover - magnetic holder.
• Possible danger related to microscopic parts of magnets can be dangerous, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Furthermore, small elements of these magnets are able to be problematic in diagnostics medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Highest magnetic holding force – what it depends on?

Breakaway force was defined for ideal contact conditions, including:

• on a plate made of structural steel, perfectly concentrating the magnetic flux
• with a cross-section minimum 10 mm
• with an ideally smooth contact surface
• with direct contact (without coatings)
• under axial application of breakaway force (90-degree angle)
• at standard ambient temperature

Practical lifting capacity: influencing factors

During everyday use, the actual holding force results from several key aspects, listed from crucial:

• Space between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by varnish or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Angle of force application – highest force is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the plate is standardly many times lower (approx. 1/5 of the lifting capacity).
• Element thickness – for full efficiency, the steel must be adequately massive. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Steel grade – the best choice is pure iron steel. Cast iron may generate lower lifting capacity.
• Plate texture – ground elements ensure maximum contact, which improves force. Rough surfaces reduce efficiency.
• Temperature – heating the magnet causes a temporary drop of force. Check the thermal limit for a given model.

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, whereas under attempts to slide the magnet the load capacity is reduced by as much as 5 times. In addition, even a small distance {between} the magnet and the plate reduces the holding force.