HH 16x5.3 [M3] / N38 - through hole magnetic holder

Strengths and weaknesses of neodymium magnets.

In addition to their magnetic capacity, neodymium magnets provide the following advantages:

• Their strength is maintained, and after around ten years it decreases only by ~1% (according to research),
• Magnets very well protect themselves against demagnetization caused by foreign field sources,
• A magnet with a metallic gold surface has better aesthetics,
• They are known for high magnetic induction at the operating surface, which affects their effectiveness,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Possibility of accurate shaping and adapting to complex needs,
• Wide application in advanced technology sectors – they are used in computer drives, drive modules, diagnostic systems, also multitasking production systems.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Disadvantages of NdFeB magnets:

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We recommend keeping them in a special holder, which not only secures them against impacts but also raises their durability
• Neodymium magnets lose 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
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• Limited possibility of making threads in the magnet and complicated shapes - preferred is a housing - magnet mounting.
• Potential hazard resulting from small fragments of magnets pose a threat, if swallowed, which gains importance in the context of child health protection. Furthermore, tiny parts of these devices are able to disrupt the diagnostic process medical after entering the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

Breakaway strength of the magnet in ideal conditions – what contributes to it?

The force parameter is a theoretical maximum value conducted under the following configuration:

• on a block made of mild steel, perfectly concentrating the magnetic flux
• whose thickness is min. 10 mm
• characterized by even structure
• under conditions of ideal adhesion (metal-to-metal)
• under axial application of breakaway force (90-degree angle)
• in stable room temperature

What influences lifting capacity in practice

In real-world applications, the actual holding force results from several key aspects, ranked from the most important:

• Gap (betwixt the magnet and the metal), because even a very small distance (e.g. 0.5 mm) leads to a decrease in force by up to 50% (this also applies to paint, rust or debris).
• Force direction – remember that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of generating force.
• Steel type – mild steel attracts best. Higher carbon content decrease magnetic properties and holding force.
• Surface structure – the more even the surface, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
• Temperature influence – hot environment reduces pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity was assessed using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under perpendicular detachment force, in contrast under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet’s surface and the plate decreases the lifting capacity.