KM HF - 22 kg - magnetic bracket

Strengths as well as weaknesses of neodymium magnets.

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

• They do not lose power, even during nearly 10 years – the drop in strength is only ~1% (based on measurements),
• They have excellent resistance to magnetism drop when exposed to external fields,
• In other words, due to the aesthetic finish of nickel, the element gains a professional look,
• They are known for high magnetic induction at the operating surface, making them more effective,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to the possibility of accurate forming and adaptation to custom projects, neodymium magnets can be created in a broad palette of geometric configurations, which makes them more universal,
• Key role in modern industrial fields – they serve a role in computer drives, motor assemblies, advanced medical instruments, and complex engineering applications.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

What to avoid - cons of neodymium magnets and ways of using them

• To avoid cracks upon strong impacts, we recommend using special steel housings. Such a solution protects the magnet and simultaneously improves its durability.
• Neodymium magnets decrease their strength 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
• They rust in a humid environment. For use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We suggest casing - magnetic mechanism, due to difficulties in producing threads inside the magnet and complex forms.
• Health risk resulting from small fragments of magnets pose a threat, in case of ingestion, which becomes key in the context of child safety. Additionally, small elements of these products can be problematic in diagnostics medical after entering the body.
• Due to complex production process, their price is relatively high,

Maximum magnetic pulling force – what contributes to it?

The specified lifting capacity represents the limit force, recorded under ideal test conditions, specifically:

• using a base made of high-permeability steel, functioning as a circuit closing element
• possessing a thickness of minimum 10 mm to ensure full flux closure
• with an ground contact surface
• without the slightest insulating layer between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• in stable room temperature

Determinants of practical lifting force of a magnet

Real force is affected by specific conditions, such as (from priority):

• Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by varnish or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Direction of force – highest force is reached only during perpendicular pulling. The force required to slide of the magnet along the surface is usually many times smaller (approx. 1/5 of the lifting capacity).
• Steel thickness – too thin steel causes magnetic saturation, causing part of the flux to be lost into the air.
• Chemical composition of the base – low-carbon steel gives the best results. Alloy steels lower magnetic permeability and lifting capacity.
• Smoothness – ideal contact is obtained only on polished steel. Any scratches and bumps reduce the real contact area, reducing force.
• Thermal factor – hot environment reduces pulling force. Exceeding the limit temperature can permanently damage the magnet.

* Lifting capacity was assessed with the use of a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, in contrast under shearing force the holding force is lower. Additionally, even a minimal clearance {between} the magnet and the plate reduces the holding force.