UMGGZ 34x6 [M4] GZ / N38 - rubber magnetic holder external thread

Pros as well as cons of NdFeB magnets.

In addition to their long-term stability, neodymium magnets provide the following advantages:

• They virtually do not lose strength, because even after 10 years the performance loss is only ~1% (according to literature),
• They are extremely resistant to demagnetization induced by external disturbances,
• Thanks to the smooth finish, the coating of nickel, gold, or silver-plated gives an professional appearance,
• Magnets are distinguished by extremely high magnetic induction on the outer layer,
• Thanks to resistance to high temperature, they can operate (depending on the shape) even at temperatures up to 230°C and higher...
• Due to the option of free molding and adaptation to individualized solutions, neodymium magnets can be produced in a variety of forms and dimensions, which amplifies use scope,
• Universal use in high-tech industry – they are commonly used in magnetic memories, electromotive mechanisms, medical devices, and multitasking production systems.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets: weaknesses and usage proposals

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only protects the magnet but also increases its resistance to damage
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Magnets exposed to a humid environment can rust. Therefore while using outdoors, we advise using waterproof magnets made of rubber, plastic or other material protecting against moisture
• Limited possibility of making threads in the magnet and complex forms - preferred is cover - magnetic holder.
• Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which is particularly important in the aspect of protecting the youngest. Furthermore, small components of these magnets are able to complicate diagnosis medical in case of swallowing.
• Due to complex production process, their price is higher than average,

Maximum lifting capacity of the magnet – what contributes to it?

The specified lifting capacity represents the peak performance, obtained under optimal environment, namely:

• using a plate made of high-permeability steel, functioning as a circuit closing element
• possessing a massiveness of min. 10 mm to avoid saturation
• with a plane cleaned and smooth
• with direct contact (no coatings)
• for force applied at a right angle (pull-off, not shear)
• at ambient temperature room level

Lifting capacity in practice – influencing factors

It is worth knowing that the magnet holding may be lower subject to the following factors, in order of importance:

• Distance (betwixt the magnet and the plate), because even a microscopic distance (e.g. 0.5 mm) leads to a reduction in force by up to 50% (this also applies to paint, rust or dirt).
• Direction of force – highest force is reached only during pulling at a 90° angle. The shear force of the magnet along the surface is standardly 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 passes through the material instead of generating force.
• Steel grade – ideal substrate is high-permeability steel. Hardened steels may attract less.
• Base smoothness – the smoother and more polished the plate, the larger the contact zone and stronger the hold. Roughness creates an air distance.
• Temperature – heating the magnet causes a temporary drop of induction. It is worth remembering the maximum operating temperature for a given model.

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under attempts to slide the magnet the holding force is lower. In addition, even a slight gap {between} the magnet and the plate lowers the lifting capacity.