UMGGZ 66x8.5 [M8] GZ / N38 - rubber magnetic holder external thread

Advantages and disadvantages of rare earth magnets.

Apart from their consistent magnetic energy, neodymium magnets have these key benefits:

• Their strength remains stable, and after approximately ten years it decreases only by ~1% (according to research),
• They show high resistance to demagnetization induced by presence of other magnetic fields,
• The use of an refined coating of noble metals (nickel, gold, silver) causes the element to look better,
• Magnets have very high magnetic induction on the surface,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to freedom in designing and the ability to adapt to unusual requirements,
• Universal use in high-tech industry – they serve a role in computer drives, electric motors, medical equipment, also industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which allows their use in miniature devices

Disadvantages of NdFeB magnets:

• At strong impacts they can break, therefore we advise placing them in special holders. A metal housing provides additional protection against damage and increases the magnet's durability.
• When exposed to high temperature, neodymium magnets experience a drop in force. Often, when the temperature exceeds 80°C, their power decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
• Due to limitations in creating threads and complicated shapes in magnets, we recommend using casing - magnetic mechanism.
• Potential hazard to health – tiny shards of magnets pose a threat, when accidentally swallowed, which is particularly important in the context of child health protection. Additionally, small components of these products are able to disrupt the diagnostic process medical when they are in the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Detachment force of the magnet in optimal conditions – what it depends on?

Information about lifting capacity was defined for optimal configuration, taking into account:

• using a sheet made of low-carbon steel, functioning as a circuit closing element
• with a thickness of at least 10 mm
• with an polished touching surface
• without any insulating layer between the magnet and steel
• during detachment in a direction vertical to the plane
• at temperature room level

Impact of factors on magnetic holding capacity in practice

It is worth knowing that the working load may be lower depending on elements below, in order of importance:

• Space between surfaces – every millimeter of separation (caused e.g. by varnish or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Metal thickness – thin material does not allow full use of the magnet. Magnetic flux passes through the material instead of generating force.
• Steel type – low-carbon steel attracts best. Alloy steels reduce magnetic permeability and holding force.
• Smoothness – ideal contact is obtained only on smooth steel. Rough texture create air cushions, reducing force.
• Thermal environment – heating the magnet results in weakening of force. Check the thermal limit for a given model.

* Lifting capacity was measured with the use of a polished steel plate of optimal thickness (min. 20 mm), under vertically applied force, in contrast under parallel forces the holding force is lower. Additionally, even a small distance {between} the magnet’s surface and the plate lowers the lifting capacity.