BM 750x180x70 [4x M8] - magnetic beam

Pros and cons of rare earth magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• Their magnetic field remains stable, and after approximately 10 years it drops only by ~1% (theoretically),
• They maintain their magnetic properties even under strong external field,
• In other words, due to the shiny surface of gold, the element becomes visually attractive,
• Magnets have exceptionally strong magnetic induction on the working surface,
• Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
• Possibility of individual shaping as well as adjusting to complex applications,
• Key role in electronics industry – they are used in hard drives, electromotive mechanisms, medical equipment, and other advanced devices.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• Susceptibility to cracking is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a special holder, which not only secures them against impacts but also increases their durability
• 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
• They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited ability of making nuts in the magnet and complex forms - recommended is casing - magnetic holder.
• Possible danger resulting from small fragments of magnets are risky, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Additionally, tiny parts of these magnets are able to complicate diagnosis medical when they are in the body.
• Due to neodymium price, their price is relatively high,

Maximum lifting capacity of the magnet – what it depends on?

The specified lifting capacity concerns the peak performance, recorded under ideal test conditions, meaning:

• using a plate made of low-carbon steel, acting as a circuit closing element
• whose transverse dimension reaches at least 10 mm
• with a plane free of scratches
• with direct contact (no coatings)
• under vertical force vector (90-degree angle)
• at ambient temperature approx. 20 degrees Celsius

Practical lifting capacity: influencing factors

Please note that the application force may be lower depending on elements below, starting with the most relevant:

• Distance (between the magnet and the metal), because even a tiny distance (e.g. 0.5 mm) results in a decrease in lifting capacity by up to 50% (this also applies to paint, corrosion or debris).
• Loading method – catalog parameter refers to pulling vertically. When applying parallel force, the magnet holds much less (typically approx. 20-30% of nominal force).
• Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet limits the attraction force (the magnet "punches through" it).
• Steel type – low-carbon steel gives the best results. Alloy steels decrease magnetic properties and holding force.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Rough surfaces reduce efficiency.
• Thermal conditions – neodymium magnets have a sensitivity to temperature. At higher temperatures they are weaker, and at low temperatures gain strength (up to a certain limit).

* Lifting capacity was measured with the use of a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, however under parallel forces the load capacity is reduced by as much as 75%. In addition, even a minimal clearance {between} the magnet’s surface and the plate reduces the lifting capacity.