BM 550x180x70 [4x M8] - magnetic beam

Pros as well as cons of rare earth magnets.

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

• They virtually do not lose power, because even after ten years the decline in efficiency is only ~1% (in laboratory conditions),
• They feature excellent resistance to magnetic field loss when exposed to external magnetic sources,
• In other words, due to the smooth layer of gold, the element gains a professional look,
• Magnets are characterized by impressive magnetic induction on the active area,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Due to the potential of accurate forming and adaptation to specialized requirements, neodymium magnets can be produced in a variety of shapes and sizes, which increases their versatility,
• Universal use in high-tech industry – they are utilized in HDD drives, brushless drives, diagnostic systems, as well as multitasking production systems.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Characteristics of disadvantages of neodymium magnets: weaknesses and usage proposals

• At very strong impacts they can crack, therefore we recommend placing them in special holders. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
• Neodymium magnets lose 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 stability even at temperatures up to 230°C
• They oxidize in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
• We suggest a housing - magnetic holder, due to difficulties in producing threads inside the magnet and complex shapes.
• Potential hazard resulting from small fragments of magnets pose a threat, if swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, small components of these devices are able to complicate diagnosis medical when they are in the body.
• High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Best holding force of the magnet in ideal parameters – what affects it?

Information about lifting capacity was determined for the most favorable conditions, including:

• using a sheet made of mild steel, serving as a ideal flux conductor
• whose transverse dimension equals approx. 10 mm
• with an polished contact surface
• with direct contact (without impurities)
• during pulling in a direction vertical to the plane
• at conditions approx. 20°C

Practical lifting capacity: influencing factors

Please note that the application force may be lower influenced by the following factors, starting with the most relevant:

• Distance (between the magnet and the metal), since even a microscopic distance (e.g. 0.5 mm) can cause a decrease in lifting capacity by up to 50% (this also applies to paint, corrosion or dirt).
• Angle of force application – highest force is available only during pulling at a 90° angle. The resistance to sliding of the magnet along the surface is typically many times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
• Chemical composition of the base – low-carbon steel gives the best results. Higher carbon content reduce magnetic permeability and lifting capacity.
• Surface finish – ideal contact is obtained only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Temperature – heating the magnet results in weakening of force. It is worth remembering the maximum operating temperature for a given model.

* Lifting capacity was determined using a polished steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, however under parallel forces the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.