UMGGW 22x6 [M4] GW / N38 - magnetic holder rubber internal thread

Advantages and disadvantages of rare earth magnets.

Apart from their notable magnetism, neodymium magnets have these key benefits:

• They do not lose power, even over around ten years – the reduction in strength is only ~1% (theoretically),
• They retain their magnetic properties even under strong external field,
• The use of an metallic coating of noble metals (nickel, gold, silver) causes the element to have aesthetics,
• Neodymium magnets achieve maximum magnetic induction on a contact point, which increases force concentration,
• Due to their durability and thermal resistance, neodymium magnets are capable of 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,
• Versatile presence in innovative solutions – they are used in computer drives, electromotive mechanisms, diagnostic systems, also other advanced devices.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• At very strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
• Neodymium magnets lose their strength under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
• Due to the susceptibility of magnets to corrosion in a humid environment, we recommend using waterproof magnets made of rubber, plastic or other material stable to moisture, in case of application outdoors
• Due to limitations in realizing threads and complex shapes in magnets, we recommend using casing - magnetic mount.
• Potential hazard related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which gains importance in the context of child safety. Furthermore, small components of these devices are able to be problematic in diagnostics medical after entering the body.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Magnetic strength at its maximum – what it depends on?

The declared magnet strength represents the limit force, obtained under optimal environment, meaning:

• using a plate made of mild steel, acting as a circuit closing element
• possessing a massiveness of minimum 10 mm to ensure full flux closure
• characterized by lack of roughness
• without the slightest air gap between the magnet and steel
• for force applied at a right angle (pull-off, not shear)
• at ambient temperature room level

Magnet lifting force in use – key factors

Bear in mind that the working load may be lower subject to the following factors, in order of importance:

• Gap between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
• Force direction – declared lifting capacity refers to detachment vertically. When attempting to slide, the magnet exhibits significantly lower power (typically approx. 20-30% of maximum force).
• Element thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet restricts the attraction force (the magnet "punches through" it).
• Chemical composition of the base – mild steel gives the best results. Higher carbon content decrease magnetic properties and holding force.
• Surface finish – full contact is possible only on smooth steel. Rough texture reduce the real contact area, weakening the magnet.
• Operating temperature – neodymium magnets have a negative temperature coefficient. When it is hot they lose power, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was performed on plates with a smooth surface of suitable thickness, under a perpendicular pulling force, in contrast under parallel forces the holding force is lower. In addition, even a small distance {between} the magnet and the plate decreases the load capacity.