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

Advantages and disadvantages of neodymium magnets.

Besides their exceptional field intensity, neodymium magnets offer the following advantages:

• They virtually do not lose power, because even after 10 years the performance loss is only ~1% (in laboratory conditions),
• They are extremely resistant to demagnetization induced by presence of other magnetic fields,
• A magnet with a shiny nickel surface looks better,
• Neodymium magnets generate maximum magnetic induction on a small surface, which allows for strong attraction,
• Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
• Possibility of exact shaping and modifying to individual requirements,
• Key role in modern technologies – they serve a role in mass storage devices, brushless drives, precision medical tools, also technologically advanced constructions.
• Relatively small size with high pulling force – neodymium magnets offer high power in small dimensions, which enables their usage in small systems

Disadvantages of neodymium magnets:

• They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets in a protective case. Such protection not only shields the magnet but also increases its resistance to damage
• We warn that neodymium magnets can lose 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 when using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
• We suggest casing - magnetic holder, due to difficulties in creating threads inside the magnet and complicated shapes.
• Potential hazard to health – tiny shards of magnets pose a threat, if swallowed, which is particularly important in the context of child health protection. It is also worth noting that tiny parts of these devices can be problematic in diagnostics medical in case of swallowing.
• With large orders the cost of neodymium magnets is a challenge,

Detachment force of the magnet in optimal conditions – what contributes to it?

The load parameter shown concerns the peak performance, measured under laboratory conditions, specifically:

• on a block made of mild steel, perfectly concentrating the magnetic flux
• possessing a thickness of min. 10 mm to avoid saturation
• characterized by smoothness
• without any air gap between the magnet and steel
• during pulling in a direction perpendicular to the mounting surface
• in neutral thermal conditions

Determinants of lifting force in real conditions

Holding efficiency impacted by specific conditions, such as (from most important):

• Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by veneer or unevenness) diminishes the pulling force, often by half at just 0.5 mm.
• Angle of force application – highest force is reached only during pulling at a 90° angle. The force required to slide of the magnet along the plate is usually several times lower (approx. 1/5 of the lifting capacity).
• Substrate thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Material type – the best choice is high-permeability steel. Hardened steels may attract less.
• Smoothness – ideal contact is obtained only on polished steel. Any scratches and bumps create air cushions, reducing force.
• Heat – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and in frost they can be stronger (up to a certain limit).

* Holding force was tested on the plate surface of 20 mm thickness, when the force acted perpendicularly, in contrast under shearing force the lifting capacity is smaller. Moreover, even a minimal clearance {between} the magnet and the plate decreases the lifting capacity.