NCM 20x13.5x5 / N38 - channel magnetic holder

Pros and cons of rare earth magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They have stable power, and over nearly 10 years their performance decreases symbolically – ~1% (in testing),
• Magnets perfectly protect themselves against demagnetization caused by ambient magnetic noise,
• A magnet with a smooth nickel surface looks better,
• Magnets have very high magnetic induction on the working surface,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Thanks to the possibility of free molding and adaptation to specialized requirements, NdFeB magnets can be produced in a variety of shapes and sizes, which expands the range of possible applications,
• Universal use in advanced technology sectors – they serve a role in data components, motor assemblies, medical equipment, as well as other advanced devices.
• Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,

Disadvantages of neodymium magnets:

• Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a strong case, which not only protects them against impacts but also increases their durability
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 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 stable to moisture, when using outdoors
• Limited ability of making nuts in the magnet and complicated shapes - recommended is a housing - magnet mounting.
• Health risk related to microscopic parts of magnets pose a threat, in case of ingestion, which is particularly important in the aspect of protecting the youngest. Furthermore, small elements of these products can disrupt the diagnostic process medical after entering the body.
• Due to complex production process, their price exceeds standard values,

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

Breakaway force was determined for the most favorable conditions, taking into account:

• with the contact of a yoke made of special test steel, ensuring full magnetic saturation
• with a cross-section no less than 10 mm
• characterized by even structure
• under conditions of ideal adhesion (surface-to-surface)
• under axial application of breakaway force (90-degree angle)
• at room temperature

Impact of factors on magnetic holding capacity in practice

In practice, the actual holding force is determined by several key aspects, presented from the most important:

• Distance – existence of any layer (rust, dirt, gap) interrupts the magnetic circuit, which lowers power steeply (even by 50% at 0.5 mm).
• Direction of force – maximum parameter is obtained only during perpendicular pulling. The force required to slide of the magnet along the plate is usually several times smaller (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin plate does not accept the full field, causing part of the power to be lost into the air.
• Material type – ideal substrate is high-permeability steel. Stainless steels may attract less.
• Surface finish – ideal contact is obtained only on smooth steel. Rough texture reduce the real contact area, reducing force.
• Heat – neodymium magnets have a negative temperature coefficient. When it is hot they are weaker, and in frost they can be stronger (up to a certain limit).

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under a perpendicular pulling force, however under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Moreover, even a slight gap {between} the magnet and the plate decreases the holding force.