UMS 16x6.5x3.5x5 / N38 - conical magnetic holder

Strengths as well as weaknesses of NdFeB magnets.

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

• They retain magnetic properties for nearly ten years – the drop is just ~1% (in theory),
• Neodymium magnets are exceptionally resistant to magnetic field loss caused by external interference,
• The use of an aesthetic coating of noble metals (nickel, gold, silver) causes the element to look better,
• Neodymium magnets generate maximum magnetic induction on a contact point, which increases force concentration,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for operation at temperatures approaching 230°C and above...
• Possibility of custom forming as well as optimizing to specific applications,
• Versatile presence in advanced technology sectors – they are utilized in hard drives, drive modules, medical devices, as well as technologically advanced constructions.
• Thanks to their power density, small magnets offer high operating force, with minimal size,

What to avoid - cons of neodymium magnets: tips and applications.

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also increases its resistance to damage
• 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 durability even at temperatures up to 230°C
• They oxidize in a humid environment - during use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
• Limited ability of making nuts in the magnet and complicated shapes - recommended is cover - magnet mounting.
• Health risk to health – tiny shards of magnets pose a threat, in case of ingestion, which is particularly important in the context of child health protection. Furthermore, small elements of these products are able to be problematic in diagnostics medical in case of swallowing.
• Due to neodymium price, their price is relatively high,

Maximum holding power of the magnet – what affects it?

Magnet power was determined for ideal contact conditions, assuming:

• using a sheet made of high-permeability steel, acting as a ideal flux conductor
• possessing a thickness of at least 10 mm to ensure full flux closure
• characterized by smoothness
• without any clearance between the magnet and steel
• during detachment in a direction vertical to the plane
• at temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

It is worth knowing that the working load may be lower depending on elements below, starting with the most relevant:

• Gap between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by varnish or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to detachment vertically. When slipping, the magnet holds significantly lower power (often approx. 20-30% of nominal force).
• Steel thickness – too thin steel does not accept the full field, causing part of the power to be wasted into the air.
• Chemical composition of the base – mild steel gives the best results. Higher carbon content decrease magnetic properties and lifting capacity.
• Plate texture – smooth surfaces guarantee perfect abutment, which improves force. Rough surfaces reduce efficiency.
• Temperature influence – hot environment weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 75%. Additionally, even a slight gap {between} the magnet’s surface and the plate reduces the load capacity.