NCM 30x13.5x5 / N38 - channel magnetic holder

Pros and cons of NdFeB magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They virtually do not lose power, because even after 10 years the decline in efficiency is only ~1% (in laboratory conditions),
• Magnets perfectly resist against loss of magnetization caused by foreign field sources,
• In other words, due to the metallic layer of nickel, the element gains a professional look,
• Magnets have impressive magnetic induction on the outer side,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Considering the ability of precise shaping and customization to unique solutions, NdFeB magnets can be manufactured in a variety of geometric configurations, which increases their versatility,
• Versatile presence in advanced technology sectors – they serve a role in mass storage devices, drive modules, medical equipment, also other advanced devices.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a special holder, which not only protects them against impacts but also increases their durability
• Neodymium magnets decrease their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. 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 creating nuts inside the magnet and complex forms.
• Possible danger to health – tiny shards of magnets can be dangerous, if swallowed, which is particularly important in the context of child health protection. Additionally, small components of these devices are able to be problematic in diagnostics medical in case of swallowing.
• High unit price – neodymium magnets are more expensive than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Maximum lifting force for a neodymium magnet – what contributes to it?

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

• using a sheet made of high-permeability steel, functioning as a magnetic yoke
• with a thickness no less than 10 mm
• characterized by smoothness
• under conditions of gap-free contact (surface-to-surface)
• during detachment in a direction perpendicular to the mounting surface
• in stable room temperature

Lifting capacity in real conditions – factors

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

• Gap between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Direction of force – maximum parameter is reached only during pulling at a 90° angle. The force required to slide of the magnet along the surface is typically several times smaller (approx. 1/5 of the lifting capacity).
• Base massiveness – too thin plate causes magnetic saturation, causing part of the power to be lost into the air.
• Material composition – not every steel reacts the same. High carbon content weaken the interaction with the magnet.
• Base smoothness – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Roughness acts like micro-gaps.
• Temperature influence – high temperature weakens pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity testing was performed on plates with a smooth surface of suitable thickness, under perpendicular forces, in contrast under shearing force the lifting capacity is smaller. In addition, even a small distance {between} the magnet and the plate reduces the load capacity.