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

Pros and cons of NdFeB magnets.

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

• They have constant strength, and over around 10 years their performance decreases symbolically – ~1% (in testing),
• Neodymium magnets prove to be exceptionally resistant to loss of magnetic properties caused by external field sources,
• A magnet with a shiny gold surface is more attractive,
• They feature high magnetic induction at the operating surface, which affects their effectiveness,
• These magnets tolerate extreme temperatures, often exceeding 230°C, when properly designed (in relation to form),
• Possibility of custom creating and adapting to concrete needs,
• Fundamental importance in modern industrial fields – they are commonly used in HDD drives, brushless drives, precision medical tools, also industrial machines.
• Thanks to concentrated force, small magnets offer high operating force, in miniature format,

Characteristics of disadvantages of neodymium magnets: application proposals

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a steel housing, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their strength 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
• They rust in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• Limited possibility of creating threads in the magnet and complicated forms - preferred is cover - mounting mechanism.
• Possible danger related to microscopic parts of magnets can be dangerous, if swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that tiny parts of these products can be problematic in diagnostics medical after entering the body.
• With budget limitations the cost of neodymium magnets can be a barrier,

Breakaway strength of the magnet in ideal conditions – what it depends on?

Magnet power is the result of a measurement for the most favorable conditions, assuming:

• on a base made of mild steel, perfectly concentrating the magnetic field
• with a thickness of at least 10 mm
• characterized by even structure
• without any air gap between the magnet and steel
• during pulling in a direction vertical to the mounting surface
• at temperature room level

Impact of factors on magnetic holding capacity in practice

Effective lifting capacity is influenced by working environment parameters, mainly (from most important):

• Gap between surfaces – every millimeter of distance (caused e.g. by veneer or dirt) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to pulling vertically. When slipping, the magnet exhibits much less (typically approx. 20-30% of nominal force).
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Steel type – low-carbon steel attracts best. Alloy steels reduce magnetic properties and holding force.
• Surface quality – the smoother and more polished the plate, the better the adhesion and stronger the hold. Roughness acts like micro-gaps.
• Thermal environment – heating the magnet results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under perpendicular forces, whereas under parallel forces the holding force is lower. Additionally, even a minimal clearance {between} the magnet and the plate decreases the holding force.