BM 510x180x70 [4x M8] - magnetic beam

Pros as well as cons of neodymium magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They do not lose magnetism, even during nearly 10 years – the drop in strength is only ~1% (based on measurements),
• They do not lose their magnetic properties even under close interference source,
• The use of an refined finish of noble metals (nickel, gold, silver) causes the element to look better,
• Magnetic induction on the top side of the magnet remains extremely intense,
• Through (appropriate) combination of ingredients, they can achieve high thermal strength, enabling functioning at temperatures reaching 230°C and above...
• Thanks to flexibility in shaping and the capacity to customize to complex applications,
• Huge importance in advanced technology sectors – they are used in HDD drives, electric motors, precision medical tools, also technologically advanced constructions.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

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 increases its resistance to damage
• Neodymium magnets decrease their power 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 durability even at temperatures up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation as well as corrosion.
• Limited possibility of producing threads in the magnet and complex forms - preferred is a housing - magnet mounting.
• Potential hazard resulting from small fragments of magnets pose a threat, if swallowed, which gains importance in the context of child health protection. Additionally, small elements of these products can complicate diagnosis medical when they are in the body.
• With budget limitations the cost of neodymium magnets can be a barrier,

Highest magnetic holding force – what it depends on?

Magnet power is the result of a measurement for the most favorable conditions, including:

• on a block made of mild steel, perfectly concentrating the magnetic flux
• possessing a thickness of minimum 10 mm to ensure full flux closure
• with an polished touching surface
• under conditions of gap-free contact (metal-to-metal)
• during pulling in a direction perpendicular to the plane
• at standard ambient temperature

Lifting capacity in real conditions – factors

Bear in mind that the working load may be lower subject to elements below, starting with the most relevant:

• Distance – the presence of foreign body (rust, tape, air) acts as an insulator, which reduces capacity steeply (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet holds much less (typically approx. 20-30% of maximum force).
• Plate thickness – too thin sheet does not close the flux, causing part of the flux to be escaped to the other side.
• Chemical composition of the base – mild steel attracts best. Higher carbon content decrease magnetic permeability and lifting capacity.
• Surface condition – smooth surfaces ensure maximum contact, which improves force. Uneven metal weaken the grip.
• Heat – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was conducted on a smooth plate of suitable thickness, under perpendicular forces, whereas under attempts to slide the magnet the holding force is lower. Moreover, even a small distance {between} the magnet and the plate decreases the lifting capacity.