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

Advantages and disadvantages of NdFeB magnets.

Besides their remarkable magnetic power, neodymium magnets offer the following advantages:

• They have unchanged lifting capacity, and over around ten years their performance decreases symbolically – ~1% (in testing),
• They have excellent resistance to magnetism drop when exposed to external magnetic sources,
• By applying a shiny layer of nickel, the element gains an elegant look,
• They show high magnetic induction at the operating surface, making them more effective,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for operation at temperatures approaching 230°C and above...
• Possibility of exact creating as well as optimizing to precise conditions,
• Universal use in future technologies – they are used in magnetic memories, motor assemblies, medical devices, as well as other advanced devices.
• Compactness – despite small sizes they generate large force, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets and ways of using them

• To avoid cracks under impact, we recommend using special steel housings. Such a solution protects the magnet and simultaneously increases its durability.
• When exposed to high temperature, neodymium magnets suffer 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 when using outdoors, we recommend using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in producing threads and complicated shapes in magnets, we propose using a housing - magnetic mount.
• Potential hazard resulting from small fragments of magnets can be dangerous, if swallowed, which gains importance in the context of child health protection. It is also worth noting that tiny parts of these magnets can complicate diagnosis 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

Maximum holding power of the magnet – what it depends on?

The force parameter is a theoretical maximum value performed under the following configuration:

• with the application of a sheet made of low-carbon steel, guaranteeing maximum field concentration
• with a cross-section minimum 10 mm
• with a plane cleaned and smooth
• under conditions of gap-free contact (metal-to-metal)
• under perpendicular force direction (90-degree angle)
• at temperature room level

Determinants of practical lifting force of a magnet

Real force is affected by specific conditions, mainly (from most important):

• Gap between magnet and steel – every millimeter of distance (caused e.g. by varnish or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Force direction – catalog parameter refers to pulling vertically. When applying parallel force, the magnet holds significantly lower power (often approx. 20-30% of maximum force).
• Base massiveness – too thin sheet causes magnetic saturation, causing part of the flux to be lost into the air.
• Steel type – mild steel attracts best. Alloy steels reduce magnetic permeability and lifting capacity.
• Surface finish – full contact is obtained only on polished steel. Any scratches and bumps create air cushions, reducing force.
• Thermal environment – heating the magnet causes a temporary drop of force. Check the maximum operating temperature for a given model.

* Lifting capacity was determined using a steel plate with a smooth surface of optimal thickness (min. 20 mm), under vertically applied force, whereas under attempts to slide the magnet the lifting capacity is smaller. Additionally, even a small distance {between} the magnet’s surface and the plate lowers the load capacity.