BM 750x180x70 [4x M8] - magnetic beam

Pros as well as cons of neodymium magnets.

Apart from their notable magnetic energy, neodymium magnets have these key benefits:

• They do not lose strength, even after around 10 years – the reduction in lifting capacity is only ~1% (based on measurements),
• They do not lose their magnetic properties even under strong external field,
• The use of an metallic finish of noble metals (nickel, gold, silver) causes the element to present itself better,
• The surface of neodymium magnets generates a powerful magnetic field – this is a distinguishing feature,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Possibility of detailed creating as well as adjusting to precise requirements,
• Significant place in electronics industry – they are commonly used in hard drives, electromotive mechanisms, precision medical tools, also other advanced devices.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which enables their usage in compact constructions

Disadvantages of neodymium magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only protects the magnet but also improves its resistance to damage
• Neodymium magnets decrease 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 durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can corrode. Therefore while using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• We suggest a housing - magnetic mount, due to difficulties in creating nuts inside the magnet and complex forms.
• Possible danger to health – tiny shards of magnets are risky, in case of ingestion, which gains importance in the aspect of protecting the youngest. Furthermore, small elements of these devices can disrupt the diagnostic process medical in case of swallowing.
• Due to neodymium price, their price is higher than average,

Highest magnetic holding force – what it depends on?

Breakaway force was determined for ideal contact conditions, assuming:

• using a plate made of high-permeability steel, acting as a magnetic yoke
• with a cross-section minimum 10 mm
• with a plane perfectly flat
• without any clearance between the magnet and steel
• during pulling in a direction perpendicular to the mounting surface
• at standard ambient temperature

What influences lifting capacity in practice

In practice, the actual lifting capacity results from a number of factors, presented from the most important:

• Air gap (betwixt 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 varnish, corrosion or debris).
• Loading method – catalog parameter refers to detachment vertically. When attempting to slide, the magnet holds much less (often approx. 20-30% of nominal force).
• Wall thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of generating force.
• Chemical composition of the base – mild steel gives the best results. Alloy admixtures decrease magnetic properties and holding force.
• Surface condition – smooth surfaces ensure maximum contact, which improves force. Rough surfaces weaken the grip.
• Operating temperature – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity was assessed by applying a steel plate with a smooth surface of suitable thickness (min. 20 mm), under perpendicular detachment force, however under attempts to slide the magnet the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate reduces the load capacity.