UMGGW 29x8 [M4] GW / N38 - magnetic holder rubber internal thread

Advantages as well as disadvantages of rare earth magnets.

Besides their magnetic performance, neodymium magnets are valued for these benefits:

• They retain full power for nearly 10 years – the drop is just ~1% (based on simulations),
• They maintain their magnetic properties even under external field action,
• The use of an shiny finish of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
• They feature high magnetic induction at the operating surface, which improves attraction properties,
• Neodymium magnets are characterized by extremely high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Due to the possibility of precise molding and customization to custom projects, NdFeB magnets can be produced in a wide range of geometric configurations, which amplifies use scope,
• Fundamental importance in high-tech industry – they are commonly used in mass storage devices, electric motors, medical devices, and multitasking production systems.
• Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

What to avoid - cons of neodymium magnets: weaknesses and usage proposals

• At strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets lose force 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
• When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation as well as corrosion.
• Limited possibility of producing threads in the magnet and complicated forms - preferred is a housing - mounting mechanism.
• Health risk resulting from small fragments of magnets pose a threat, if swallowed, which becomes key in the context of child health protection. It is also worth noting that small elements of these products are able to be problematic in diagnostics medical when they are in the body.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

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

The load parameter shown represents the limit force, recorded under laboratory conditions, meaning:

• on a block made of mild steel, optimally conducting the magnetic flux
• whose thickness reaches at least 10 mm
• with an polished contact surface
• under conditions of ideal adhesion (surface-to-surface)
• under axial force direction (90-degree angle)
• at conditions approx. 20°C

Lifting capacity in real conditions – factors

Real force is affected by working environment parameters, mainly (from most important):

• Gap (between the magnet and the plate), because even a tiny distance (e.g. 0.5 mm) leads to a drastic drop in force by up to 50% (this also applies to paint, corrosion or dirt).
• Load vector – highest force is available only during perpendicular pulling. The resistance to sliding of the magnet along the plate is typically many times lower (approx. 1/5 of the lifting capacity).
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Material type – ideal substrate is pure iron steel. Hardened steels may have worse magnetic properties.
• Surface condition – smooth surfaces guarantee perfect abutment, which increases field saturation. Rough surfaces reduce efficiency.
• Operating temperature – NdFeB sinters have a negative temperature coefficient. At higher temperatures they lose power, and in frost they can be stronger (up to a certain limit).

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