UMGW 36x18x8 [M8] GW / N38 - magnetic holder internal thread

Strengths and weaknesses of rare earth magnets.

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

• They do not lose strength, even after nearly 10 years – the drop in strength is only ~1% (according to tests),
• They possess excellent resistance to weakening of magnetic properties due to opposing magnetic fields,
• Thanks to the elegant finish, the plating of nickel, gold, or silver gives an elegant appearance,
• Neodymium magnets deliver maximum magnetic induction on a their surface, which increases force concentration,
• Through (appropriate) combination of ingredients, they can achieve high thermal resistance, allowing for operation at temperatures approaching 230°C and above...
• In view of the ability of flexible forming and adaptation to unique projects, magnetic components can be created in a broad palette of shapes and sizes, which makes them more universal,
• Huge importance in high-tech industry – they are used in computer drives, electric motors, medical equipment, and industrial machines.
• Thanks to their power density, small magnets offer high operating force, in miniature format,

Disadvantages of neodymium magnets:

• They are prone to damage upon too strong impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only protects the magnet but also increases its resistance to damage
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material protecting against moisture
• We suggest a housing - magnetic mechanism, due to difficulties in realizing nuts inside the magnet and complex forms.
• Possible danger related to microscopic parts of magnets are risky, in case of ingestion, which becomes key in the aspect of protecting the youngest. Additionally, small elements of these magnets can complicate diagnosis medical after entering the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Highest magnetic holding force – what affects it?

The specified lifting capacity refers to the limit force, obtained under ideal test conditions, namely:

• on a plate made of structural steel, perfectly concentrating the magnetic flux
• with a thickness no less than 10 mm
• with an ideally smooth contact surface
• under conditions of ideal adhesion (metal-to-metal)
• during detachment in a direction perpendicular to the mounting surface
• in temp. approx. 20°C

Practical lifting capacity: influencing factors

Holding efficiency impacted by specific conditions, mainly (from most important):

• Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by varnish or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the nominal value.
• Substrate thickness – for full efficiency, the steel must be adequately massive. Thin sheet limits the lifting capacity (the magnet "punches through" it).
• Chemical composition of the base – low-carbon steel gives the best results. Higher carbon content lower magnetic permeability and lifting capacity.
• Base smoothness – the smoother and more polished the surface, the larger the contact zone and higher the lifting capacity. Roughness creates an air distance.
• Heat – neodymium magnets have a sensitivity to temperature. At higher temperatures they lose power, and at low temperatures they can be stronger (up to a certain limit).

* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, whereas under parallel forces the lifting capacity is smaller. Moreover, even a small distance {between} the magnet and the plate reduces the load capacity.