UMGW 48x24x11.5 [M8] GW / N38 - magnetic holder internal thread

Advantages and disadvantages of neodymium magnets NdFeB.

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

• They do not lose their strength approximately 10 years – the loss of strength is only ~1% (based on measurements),
• They show exceptional resistance to demagnetization from outside magnetic sources,
• By applying a shiny layer of gold, the element gains a sleek look,
• The outer field strength of the magnet shows elevated magnetic properties,
• These magnets tolerate extreme temperatures, often exceeding 230°C, when properly designed (in relation to form),
• With the option for fine forming and targeted design, these magnets can be produced in multiple shapes and sizes, greatly improving design adaptation,
• Key role in advanced technical fields – they are used in computer drives, electric motors, clinical machines and other advanced devices,
• Relatively small size with high magnetic force – neodymium magnets offer strong power in tiny dimensions, which allows for use in small systems

Disadvantages of rare earth magnets:

• They can break when subjected to a strong impact. If the magnets are exposed to physical collisions, it is advisable to use in a protective enclosure. The steel housing, in the form of a holder, protects the magnet from breakage while also reinforces its overall resistance,
• They lose power at elevated temperatures. Most neodymium magnets experience permanent loss in strength when heated above 80°C (depending on the shape and height). However, we offer special variants with high temperature resistance that can operate up to 230°C or higher,
• Magnets exposed to wet conditions can rust. Therefore, for outdoor applications, we suggest waterproof types made of non-metallic composites,
• Using a cover – such as a magnetic holder – is advised due to the challenges in manufacturing fine shapes directly in the magnet,
• Possible threat from tiny pieces may arise, especially if swallowed, which is notable in the family environments. Furthermore, miniature parts from these assemblies might complicate medical imaging after being swallowed,
• High unit cost – neodymium magnets are more expensive than other types of magnets (e.g., ferrite), which may limit large-scale applications

Breakaway strength of the magnet in ideal conditions – what affects it?

The given holding capacity of the magnet means the highest holding force, determined under optimal conditions, that is:

• with the use of low-carbon steel plate serving as a magnetic yoke
• of a thickness of at least 10 mm
• with a refined outer layer
• in conditions of no clearance
• under perpendicular detachment force
• at room temperature

Lifting capacity in real conditions – factors

In practice, the holding capacity of a magnet is affected by these factors, arranged from the most important to the least relevant:

• Air gap between the magnet and the plate, as even a very small distance (e.g. 0.5 mm) causes a drop in lifting force of up to 50%.
• Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
• Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
• Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
• Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
• Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Holding force was measured on the plate surface of 20 mm thickness, when a perpendicular force was applied, in contrast under parallel forces the holding force is lower. In addition, even a slight gap {between} the magnet and the plate decreases the load capacity.