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

Pros and cons of rare earth magnets.

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

• They have constant strength, and over around 10 years their performance decreases symbolically – ~1% (in testing),
• They feature excellent resistance to magnetism drop as a result of external magnetic sources,
• In other words, due to the shiny layer of nickel, the element is aesthetically pleasing,
• Magnetic induction on the top side of the magnet turns out to be very high,
• Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of exact machining as well as optimizing to complex applications,
• Fundamental importance in innovative solutions – they serve a role in mass storage devices, drive modules, medical devices, as well as technologically advanced constructions.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• Neodymium magnets decrease their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures 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
• We suggest a housing - magnetic holder, due to difficulties in realizing threads inside the magnet and complex shapes.
• Possible danger related to microscopic parts of magnets are risky, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Furthermore, small elements of these magnets can disrupt the diagnostic process medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which hinders application in large quantities

Maximum lifting capacity of the magnet – what contributes to it?

Information about lifting capacity was determined for ideal contact conditions, including:

• on a base made of mild steel, perfectly concentrating the magnetic flux
• whose transverse dimension reaches at least 10 mm
• with an ground touching surface
• under conditions of ideal adhesion (surface-to-surface)
• during detachment in a direction perpendicular to the mounting surface
• at room temperature

Lifting capacity in practice – influencing factors

Real force impacted by specific conditions, mainly (from most important):

• Clearance – existence of foreign body (rust, tape, air) interrupts the magnetic circuit, which reduces power steeply (even by 50% at 0.5 mm).
• Force direction – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Material composition – different alloys attracts identically. High carbon content weaken the attraction effect.
• Surface condition – ground elements ensure maximum contact, which improves field saturation. Rough surfaces weaken the grip.
• Thermal environment – temperature increase results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity was determined with the use of a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular detachment force, whereas under parallel forces the load capacity is reduced by as much as 75%. Moreover, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.