BM 550x180x70 [4x M8] - magnetic beam

Advantages as well as disadvantages of rare earth magnets.

Besides their exceptional strength, neodymium magnets offer the following advantages:

• Their strength is durable, and after around 10 years it drops only by ~1% (according to research),
• They are noted for resistance to demagnetization induced by external magnetic fields,
• A magnet with a smooth silver surface has an effective appearance,
• The surface of neodymium magnets generates a unique magnetic field – this is one of their assets,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, enabling action at temperatures approaching 230°C and above...
• In view of the possibility of flexible shaping and customization to individualized solutions, NdFeB magnets can be produced in a variety of geometric configurations, which amplifies use scope,
• Huge importance in innovative solutions – they are utilized in magnetic memories, drive modules, precision medical tools, and multitasking production systems.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Problematic aspects of neodymium magnets: application proposals

• Brittleness is one of their disadvantages. Upon strong impact they can fracture. We advise keeping them in a steel housing, which not only secures them against impacts but also raises their durability
• We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which secure oxidation as well as corrosion.
• We recommend cover - magnetic holder, due to difficulties in producing threads inside the magnet and complex forms.
• Potential hazard related to microscopic parts of magnets pose a threat, when accidentally swallowed, which becomes key in the context of child health protection. Furthermore, small components of these products can be problematic in diagnostics medical after entering the body.
• Due to neodymium price, their price is higher than average,

Maximum magnetic pulling force – what contributes to it?

Breakaway force is the result of a measurement for optimal configuration, assuming:

• with the use of a sheet made of low-carbon steel, ensuring maximum field concentration
• possessing a massiveness of at least 10 mm to ensure full flux closure
• with an ground contact surface
• under conditions of no distance (metal-to-metal)
• under vertical application of breakaway force (90-degree angle)
• in neutral thermal conditions

What influences lifting capacity in practice

Please note that the magnet holding will differ influenced by the following factors, in order of importance:

• Clearance – existence of any layer (paint, tape, air) acts as an insulator, which lowers power steeply (even by 50% at 0.5 mm).
• Direction of force – highest force is obtained only during perpendicular pulling. The shear force of the magnet along the surface is usually several times smaller (approx. 1/5 of the lifting capacity).
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Plate material – low-carbon steel attracts best. Alloy steels decrease magnetic properties and lifting capacity.
• Surface finish – full contact is possible only on smooth steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Thermal conditions – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and at low temperatures they can be stronger (up to a certain limit).

* Lifting capacity testing was performed on plates with a smooth surface of optimal thickness, under perpendicular forces, whereas under shearing force the lifting capacity is smaller. Moreover, even a slight gap {between} the magnet’s surface and the plate reduces the load capacity.