KM HF - 22 kg - magnetic bracket

Strengths as well as weaknesses of NdFeB magnets.

Besides their durability, neodymium magnets are valued for these benefits:

• They retain magnetic properties for around ten years – the loss is just ~1% (according to analyses),
• They retain their magnetic properties even under external field action,
• Thanks to the shiny finish, the coating of nickel, gold-plated, or silver gives an modern appearance,
• Magnets are distinguished by exceptionally strong magnetic induction on the working surface,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling action at temperatures reaching 230°C and above...
• Thanks to versatility in forming and the capacity to customize to unusual requirements,
• Universal use in high-tech industry – they are used in mass storage devices, drive modules, precision medical tools, also modern systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• To avoid cracks upon strong impacts, we recommend using special steel holders. Such a solution protects the magnet and simultaneously increases its durability.
• When exposed to high temperature, neodymium magnets suffer a drop in power. 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
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• We suggest a housing - magnetic holder, due to difficulties in producing nuts inside the magnet and complex shapes.
• Potential hazard related to microscopic parts of magnets are risky, if swallowed, which is particularly important in the context of child safety. Additionally, small elements of these magnets can complicate diagnosis medical after entering the body.
• With mass production the cost of neodymium magnets is a challenge,

Maximum magnetic pulling force – what affects it?

Holding force of 22 kg is a result of laboratory testing conducted under the following configuration:

• with the application of a sheet made of low-carbon steel, ensuring maximum field concentration
• whose transverse dimension equals approx. 10 mm
• characterized by lack of roughness
• under conditions of gap-free contact (surface-to-surface)
• during detachment in a direction perpendicular to the mounting surface
• at ambient temperature approx. 20 degrees Celsius

Determinants of lifting force in real conditions

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

• Clearance – existence of foreign body (paint, tape, air) acts as an insulator, which lowers capacity rapidly (even by 50% at 0.5 mm).
• Force direction – catalog parameter refers to detachment vertically. When attempting to slide, the magnet exhibits much less (often approx. 20-30% of nominal force).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field passes through the material instead of generating force.
• Steel type – low-carbon steel gives the best results. Higher carbon content decrease magnetic permeability and lifting capacity.
• Surface finish – ideal contact is possible only on polished steel. Rough texture reduce the real contact area, reducing force.
• Temperature – temperature increase causes a temporary drop of force. Check the thermal limit for a given model.

* Lifting capacity was determined by applying a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, however under attempts to slide the magnet the holding force is lower. In addition, even a slight gap {between} the magnet’s surface and the plate reduces the load capacity.