UMGGW 34x8 [M4] GW / N38 - magnetic holder rubber internal thread

Pros as well as cons of NdFeB magnets.

Besides their stability, neodymium magnets are valued for these benefits:

• They do not lose power, even after approximately ten years – the drop in lifting capacity is only ~1% (theoretically),
• They do not lose their magnetic properties even under close interference source,
• Thanks to the elegant finish, the coating of nickel, gold-plated, or silver gives an visually attractive appearance,
• They show high magnetic induction at the operating surface, which affects their effectiveness,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, enabling operation at temperatures reaching 230°C and above...
• Possibility of individual machining as well as modifying to concrete requirements,
• Universal use in advanced technology sectors – they are commonly used in mass storage devices, motor assemblies, diagnostic systems, also technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in compact dimensions, which makes them useful in small systems

Disadvantages of NdFeB magnets:

• At strong impacts they can crack, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape and 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
• Magnets exposed to a humid environment can rust. Therefore during using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• We recommend casing - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complex forms.
• Possible danger related to microscopic parts of magnets can be dangerous, in case of ingestion, which becomes key in the context of child health protection. Additionally, tiny parts of these magnets can complicate diagnosis medical in case of swallowing.
• Due to complex production process, their price is higher than average,

Maximum magnetic pulling force – what affects it?

The lifting capacity listed is a measurement result performed under specific, ideal conditions:

• on a block made of mild steel, optimally conducting the magnetic flux
• possessing a thickness of minimum 10 mm to avoid saturation
• with an ground touching surface
• without any air gap between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• at ambient temperature approx. 20 degrees Celsius

Practical aspects of lifting capacity – factors

In real-world applications, the real power depends on many variables, presented from the most important:

• Clearance – the presence of foreign body (rust, dirt, air) acts as an insulator, which lowers capacity steeply (even by 50% at 0.5 mm).
• Force direction – catalog parameter refers to detachment vertically. When slipping, the magnet holds much less (often approx. 20-30% of nominal force).
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Plate material – mild steel attracts best. Higher carbon content lower magnetic permeability and holding force.
• Smoothness – ideal contact is possible only on polished steel. Any scratches and bumps create air cushions, weakening the magnet.
• Temperature influence – high temperature reduces magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under attempts to slide the magnet the load capacity is reduced by as much as 75%. Moreover, even a slight gap {between} the magnet and the plate reduces the holding force.