NCM 40x13.5x5 / N38 - channel magnetic holder

Advantages as well as disadvantages of neodymium magnets.

Apart from their consistent power, neodymium magnets have these key benefits:

• They have constant strength, and over around ten years their performance decreases symbolically – ~1% (in testing),
• Magnets effectively resist against demagnetization caused by ambient magnetic noise,
• By covering with a shiny layer of gold, the element has an elegant look,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to the possibility of accurate forming and adaptation to custom requirements, magnetic components can be created in a wide range of geometric configurations, which expands the range of possible applications,
• Fundamental importance in advanced technology sectors – they find application in computer drives, electric drive systems, medical equipment, and industrial machines.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets and ways of using them

• They are prone to damage 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
• When exposed to high temperature, neodymium magnets experience a drop in strength. 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 stable to moisture, in case of application outdoors
• Due to limitations in creating threads and complex forms in magnets, we recommend using cover - magnetic mount.
• Potential hazard resulting from small fragments of magnets can be dangerous, in case of ingestion, which becomes key in the context of child safety. Additionally, small elements of these magnets can complicate diagnosis 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 specified lifting capacity represents the limit force, recorded under laboratory conditions, meaning:

• on a plate made of mild steel, perfectly concentrating the magnetic field
• possessing a thickness of at least 10 mm to ensure full flux closure
• characterized by even structure
• with zero gap (no paint)
• under axial force direction (90-degree angle)
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

Please note that the magnet holding will differ subject to elements below, in order of importance:

• Space between magnet and steel – even a fraction of a millimeter of separation (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Force direction – remember that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Base massiveness – insufficiently thick sheet does not close the flux, causing part of the flux to be lost to the other side.
• Steel grade – the best choice is high-permeability steel. Cast iron may attract less.
• Surface finish – ideal contact is obtained only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Operating temperature – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.