UMGGW 88x8.5 [M6] GW / N38 - magnetic holder rubber internal thread

Advantages and disadvantages of rare earth magnets.

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

• They do not lose magnetism, even after nearly 10 years – the drop in strength is only ~1% (according to tests),
• They do not lose their magnetic properties even under strong external field,
• Thanks to the shimmering finish, the surface of nickel, gold, or silver-plated gives an modern appearance,
• Magnets are characterized by exceptionally strong magnetic induction on the working surface,
• Through (adequate) combination of ingredients, they can achieve high thermal resistance, allowing for operation at temperatures approaching 230°C and above...
• Possibility of accurate machining and adjusting to individual requirements,
• Fundamental importance in electronics industry – they are commonly used in data components, motor assemblies, advanced medical instruments, also modern systems.
• Thanks to their power density, small magnets offer high operating force, occupying minimum space,

Drawbacks and weaknesses of neodymium magnets: tips and applications.

• They are prone to damage upon heavy 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
• When exposed to high temperature, neodymium magnets experience a drop in strength. 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
• 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 ability of producing nuts in the magnet and complicated shapes - preferred is cover - magnetic holder.
• Health risk related to microscopic parts of magnets are risky, if swallowed, which becomes key in the context of child health protection. Furthermore, small elements of these devices can be problematic in diagnostics medical in case of swallowing.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Best holding force of the magnet in ideal parameters – what it depends on?

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

• with the application of a yoke made of low-carbon steel, ensuring full magnetic saturation
• possessing a massiveness of min. 10 mm to avoid saturation
• characterized by even structure
• with zero gap (without coatings)
• for force applied at a right angle (pull-off, not shear)
• in neutral thermal conditions

Determinants of lifting force in real conditions

Please note that the working load may be lower influenced by the following factors, in order of importance:

• Distance – existence of any layer (rust, tape, gap) interrupts the magnetic circuit, which lowers capacity steeply (even by 50% at 0.5 mm).
• Force direction – note that the magnet has greatest strength perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the maximum value.
• Wall thickness – the thinner the sheet, the weaker the hold. Magnetic flux passes through the material instead of generating force.
• Material composition – different alloys reacts the same. High carbon content worsen the interaction with the magnet.
• Smoothness – full contact is possible only on smooth steel. Any scratches and bumps create air cushions, reducing force.
• Thermal factor – hot environment weakens pulling force. Too high temperature can permanently damage the magnet.

* Lifting capacity was assessed using a smooth steel plate of optimal thickness (min. 20 mm), under vertically applied force, whereas under shearing force the lifting capacity is smaller. In addition, even a minimal clearance {between} the magnet’s surface and the plate lowers the load capacity.