BM 950x180x70 [4x M8] - magnetic beam

Advantages and disadvantages of rare earth magnets.

Apart from their superior magnetism, neodymium magnets have these key benefits:

• They have unchanged lifting capacity, and over around ten years their performance decreases symbolically – ~1% (according to theory),
• Magnets perfectly defend themselves against demagnetization caused by foreign field sources,
• A magnet with a smooth silver surface has better aesthetics,
• The surface of neodymium magnets generates a intense magnetic field – this is a distinguishing feature,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
• Possibility of detailed shaping and adjusting to specific needs,
• Universal use in future technologies – they find application in mass storage devices, electromotive mechanisms, advanced medical instruments, and modern systems.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Characteristics of disadvantages of neodymium magnets and proposals for their use:

• They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only protects the magnet but also increases its resistance to damage
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Limited possibility of making nuts in the magnet and complex shapes - recommended is cover - mounting mechanism.
• Potential hazard resulting from small fragments of magnets can be dangerous, in case of ingestion, which becomes key in the context of child safety. Additionally, tiny parts of these magnets can be problematic in diagnostics medical when they are in the body.
• Due to neodymium price, their price exceeds standard values,

Magnetic strength at its maximum – what it depends on?

Magnet power was determined for the most favorable conditions, taking into account:

• using a sheet made of mild steel, acting as a circuit closing element
• possessing a massiveness of min. 10 mm to ensure full flux closure
• with a surface perfectly flat
• under conditions of no distance (metal-to-metal)
• for force acting at a right angle (in the magnet axis)
• at conditions approx. 20°C

Determinants of practical lifting force of a magnet

Please note that the working load will differ depending on the following factors, starting with the most relevant:

• Distance – existence of any layer (rust, tape, gap) acts as an insulator, which reduces capacity rapidly (even by 50% at 0.5 mm).
• Force direction – catalog parameter refers to detachment vertically. When attempting to slide, the magnet holds significantly lower power (typically approx. 20-30% of nominal force).
• Plate thickness – insufficiently thick sheet causes magnetic saturation, causing part of the power to be escaped into the air.
• Material type – the best choice is pure iron steel. Cast iron may attract less.
• Smoothness – ideal contact is possible only on polished steel. Any scratches and bumps reduce the real contact area, weakening the magnet.
• Temperature – heating the magnet causes a temporary drop of induction. Check the thermal limit for a given model.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under attempts to slide the magnet the load capacity is reduced by as much as fivefold. In addition, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.