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

Pros and cons of rare earth magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• They have unchanged lifting capacity, and over nearly ten years their attraction force decreases symbolically – ~1% (in testing),
• Magnets very well protect themselves against demagnetization caused by external fields,
• A magnet with a metallic nickel surface has an effective appearance,
• They feature high magnetic induction at the operating surface, which increases their power,
• Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of detailed creating and optimizing to precise needs,
• Huge importance in modern technologies – they serve a role in hard drives, electric drive systems, medical equipment, and industrial machines.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Cons of neodymium magnets and proposals for their use:

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a steel housing, which not only secures them against impacts but also increases their durability
• When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• We suggest a housing - magnetic mount, due to difficulties in realizing threads inside the magnet and complicated shapes.
• Health risk related to microscopic parts of magnets can be dangerous, when accidentally 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 be problematic in diagnostics medical when they are in the body.
• Due to complex production process, their price exceeds standard values,

Maximum lifting capacity of the magnet – what it depends on?

Magnet power was determined for the most favorable conditions, taking into account:

• with the use of a sheet made of special test steel, guaranteeing maximum field concentration
• whose transverse dimension reaches at least 10 mm
• with an ideally smooth touching surface
• without the slightest clearance between the magnet and steel
• during pulling in a direction vertical to the mounting surface
• at ambient temperature room level

Determinants of practical lifting force of a magnet

During everyday use, the actual lifting capacity results from several key aspects, ranked from most significant:

• Distance (betwixt the magnet and the metal), as even a very small distance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Load vector – highest force is reached only during perpendicular pulling. The resistance to sliding of the magnet along the surface is usually many times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of converting into lifting capacity.
• Steel grade – ideal substrate is high-permeability steel. Hardened steels may generate lower lifting capacity.
• Base smoothness – the more even the surface, the larger the contact zone and higher the lifting capacity. Roughness creates an air distance.
• Thermal environment – heating the magnet causes a temporary drop of induction. Check the maximum operating temperature for a given model.

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under parallel forces the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate lowers the load capacity.