RM R7 SUPER - 13000 Gs / N52 - magnetic distributor

Advantages and disadvantages of neodymium magnets.

Besides their remarkable strength, neodymium magnets offer the following advantages:

• They retain magnetic properties for nearly ten years – the loss is just ~1% (according to analyses),
• They retain their magnetic properties even under close interference source,
• The use of an metallic coating of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Magnets exhibit very high magnetic induction on the surface,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Thanks to freedom in shaping and the capacity to modify to client solutions,
• Significant place in electronics industry – they find application in magnetic memories, motor assemblies, diagnostic systems, and modern systems.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only shields the magnet but also increases its resistance to damage
• NdFeB magnets lose force when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop 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 extremely resistant to heat
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation and corrosion.
• We suggest a housing - magnetic mechanism, due to difficulties in creating threads inside the magnet and complicated forms.
• Health risk related to microscopic parts of magnets pose a threat, if swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that small elements of these magnets are able to disrupt the diagnostic process medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Best holding force of the magnet in ideal parameters – what contributes to it?

The declared magnet strength concerns the limit force, recorded under optimal environment, specifically:

• on a block made of mild steel, effectively closing the magnetic field
• whose thickness is min. 10 mm
• with an ideally smooth contact surface
• without the slightest insulating layer between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• in stable room temperature

Impact of factors on magnetic holding capacity in practice

Real force is affected by specific conditions, such as (from most important):

• Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by varnish or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Angle of force application – maximum parameter is available only during pulling at a 90° angle. The shear force of the magnet along the plate is typically several times smaller (approx. 1/5 of the lifting capacity).
• Element thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Material composition – different alloys reacts the same. Alloy additives weaken the attraction effect.
• Base smoothness – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Unevenness creates an air distance.
• Heat – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Holding force was measured on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Additionally, even a minimal clearance {between} the magnet and the plate reduces the lifting capacity.