UMGZ 20x15x7 [M4] GZ / N38 - magnetic holder external thread

Pros as well as cons of rare earth magnets.

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

• They have unchanged lifting capacity, and over more than ten years their attraction force decreases symbolically – ~1% (in testing),
• They have excellent resistance to magnetism drop when exposed to opposing magnetic fields,
• In other words, due to the glossy surface of nickel, the element becomes visually attractive,
• Neodymium magnets deliver maximum magnetic induction on a small surface, which allows for strong attraction,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
• Thanks to freedom in forming and the ability to modify to specific needs,
• Versatile presence in advanced technology sectors – they are commonly used in magnetic memories, motor assemblies, advanced medical instruments, as well as complex engineering applications.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Disadvantages of neodymium magnets:

• At very strong impacts they can break, therefore we recommend placing them in strong housings. A metal housing provides additional protection against damage and increases the magnet's durability.
• We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material immune to moisture, in case of application outdoors
• We suggest casing - magnetic mount, due to difficulties in realizing threads inside the magnet and complicated shapes.
• Possible danger to health – tiny shards of magnets can be dangerous, when accidentally swallowed, which becomes key in the context of child health protection. Additionally, small components of these products are able to be problematic in diagnostics medical when they are in the body.
• With mass production the cost of neodymium magnets is economically unviable,

Magnetic strength at its maximum – what affects it?

Breakaway force was defined for the most favorable conditions, taking into account:

• on a plate made of mild steel, perfectly concentrating the magnetic flux
• with a thickness no less than 10 mm
• with an ground touching surface
• with total lack of distance (no impurities)
• during pulling in a direction perpendicular to the mounting surface
• in stable room temperature

Lifting capacity in real conditions – factors

In practice, the actual lifting capacity depends on a number of factors, ranked from the most important:

• Gap between surfaces – even a fraction of a millimeter of separation (caused e.g. by varnish or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops drastically, often to levels of 20-30% of the maximum value.
• Base massiveness – insufficiently thick steel does not accept the full field, causing part of the flux to be wasted to the other side.
• Steel grade – the best choice is high-permeability steel. Cast iron may generate lower lifting capacity.
• Surface quality – the more even the plate, the better the adhesion and higher the lifting capacity. Roughness acts like micro-gaps.
• Temperature influence – high temperature reduces magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Additionally, even a minimal clearance {between} the magnet and the plate lowers the holding force.