UMGGZ 88x8.5 [M8] GZ / N38 - rubber magnetic holder external thread

Advantages as well as disadvantages of rare earth magnets.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They do not lose magnetism, even during nearly 10 years – the drop in power is only ~1% (theoretically),
• Neodymium magnets prove to be remarkably resistant to magnetic field loss caused by external interference,
• By covering with a lustrous layer of nickel, the element acquires an elegant look,
• Magnetic induction on the top side of the magnet remains impressive,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to modularity in constructing and the ability to modify to unusual requirements,
• Versatile presence in modern technologies – they are used in mass storage devices, brushless drives, medical equipment, and industrial machines.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

What to avoid - cons of neodymium magnets and ways of using them

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only protects the magnet but also increases its resistance to damage
• NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
• They rust in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend cover - magnetic mount, due to difficulties in creating nuts inside the magnet and complex forms.
• Possible danger related to microscopic parts of magnets are risky, in case of ingestion, which becomes key in the aspect of protecting the youngest. Furthermore, tiny parts of these magnets can be problematic in diagnostics medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Magnetic strength at its maximum – what contributes to it?

The force parameter is a measurement result executed under specific, ideal conditions:

• using a sheet made of mild steel, functioning as a circuit closing element
• whose transverse dimension reaches at least 10 mm
• with an ideally smooth contact surface
• without any clearance between the magnet and steel
• during pulling in a direction perpendicular to the plane
• at ambient temperature approx. 20 degrees Celsius

What influences lifting capacity in practice

In real-world applications, the actual holding force results from many variables, ranked from the most important:

• Gap between surfaces – even a fraction of a millimeter of distance (caused e.g. by varnish or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
• Load vector – highest force is reached only during pulling at a 90° angle. The force required to slide of the magnet along the plate is usually many times smaller (approx. 1/5 of the lifting capacity).
• Plate thickness – insufficiently thick steel does not accept the full field, causing part of the flux to be lost into the air.
• Steel type – low-carbon steel attracts best. Higher carbon content reduce magnetic properties and lifting capacity.
• Surface condition – smooth surfaces ensure maximum contact, which improves field saturation. Uneven metal weaken the grip.
• Thermal factor – hot environment reduces magnetic field. Too high temperature can permanently damage the magnet.

* Lifting capacity testing was carried out on plates with a smooth surface of optimal thickness, under a perpendicular pulling force, in contrast under attempts to slide the magnet the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet’s surface and the plate reduces the load capacity.