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

Strengths and weaknesses of rare earth magnets.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They retain magnetic properties for almost ten years – the loss is just ~1% (in theory),
• They have excellent resistance to magnetic field loss when exposed to external fields,
• The use of an shiny coating of noble metals (nickel, gold, silver) causes the element to present itself better,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
• Thanks to freedom in designing and the capacity to adapt to unusual requirements,
• Fundamental importance in high-tech industry – they are commonly used in HDD drives, motor assemblies, medical devices, as well as multitasking production systems.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which enables their usage in compact constructions

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a strong case, which not only secures them against impacts but also increases their durability
• We warn that neodymium magnets can lose their strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 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, when using outdoors
• Limited ability of producing nuts in the magnet and complicated shapes - recommended is cover - mounting mechanism.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which gains importance in the context of child safety. Furthermore, tiny parts of these magnets can complicate diagnosis medical after entering the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which can limit application in large quantities

Detachment force of the magnet in optimal conditions – what it depends on?

Information about lifting capacity was defined for optimal configuration, assuming:

• on a base made of mild steel, optimally conducting the magnetic field
• whose transverse dimension is min. 10 mm
• characterized by lack of roughness
• without the slightest air gap between the magnet and steel
• under axial application of breakaway force (90-degree angle)
• in neutral thermal conditions

Practical aspects of lifting capacity – factors

Effective lifting capacity is affected by working environment parameters, including (from priority):

• Distance (between the magnet and the plate), since even a microscopic distance (e.g. 0.5 mm) can cause a drastic drop in lifting capacity by up to 50% (this also applies to paint, corrosion or dirt).
• Loading method – declared lifting capacity refers to detachment vertically. When slipping, the magnet holds significantly lower power (often approx. 20-30% of maximum force).
• Element thickness – for full efficiency, the steel must be sufficiently thick. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Material composition – not every steel reacts the same. High carbon content worsen the attraction effect.
• Surface condition – ground elements guarantee perfect abutment, which improves force. Rough surfaces reduce efficiency.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. At higher temperatures 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, however under parallel forces the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.