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

Pros as well as cons of rare earth magnets.

Besides their high retention, neodymium magnets are valued for these benefits:

• They retain full power for almost ten years – the loss is just ~1% (in theory),
• They possess excellent resistance to magnetism drop when exposed to external magnetic sources,
• Thanks to the metallic finish, the surface of nickel, gold-plated, or silver-plated gives an visually attractive appearance,
• Magnets are characterized by extremely high magnetic induction on the outer side,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can function (depending on the form) even at a temperature of 230°C or more...
• Possibility of accurate creating as well as modifying to individual requirements,
• Huge importance in innovative solutions – they serve a role in HDD drives, brushless drives, diagnostic systems, also industrial machines.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Drawbacks and weaknesses of neodymium magnets and ways of using them

• Brittleness is one of their disadvantages. Upon strong impact they can break. We advise keeping them in a strong case, which not only secures them against impacts but also raises their durability
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we recommend our specialized [AH] magnets, which work effectively even at 230°C.
• When exposed to humidity, magnets usually rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation and corrosion.
• Limited possibility of producing threads in the magnet and complicated shapes - recommended is a housing - magnet mounting.
• Potential hazard to health – tiny shards of magnets are risky, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Furthermore, tiny parts of these devices can complicate diagnosis medical after entering the body.
• Due to expensive raw materials, their price is higher than average,

Maximum lifting capacity of the magnet – what affects it?

The specified lifting capacity concerns the maximum value, recorded under laboratory conditions, specifically:

• with the application of a sheet made of low-carbon steel, guaranteeing full magnetic saturation
• whose thickness equals approx. 10 mm
• with an polished contact surface
• with direct contact (without paint)
• under perpendicular application of breakaway force (90-degree angle)
• in neutral thermal conditions

Key elements affecting lifting force

In practice, the actual lifting capacity results from several key aspects, presented from the most important:

• Space between surfaces – every millimeter of distance (caused e.g. by veneer or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
• Direction of force – highest force is reached only during pulling at a 90° angle. The force required to slide of the magnet along the surface is usually many times smaller (approx. 1/5 of the lifting capacity).
• Steel thickness – insufficiently thick steel does not accept the full field, causing part of the flux to be wasted to the other side.
• Plate material – mild steel gives the best results. Alloy admixtures lower magnetic permeability and lifting capacity.
• Surface condition – smooth surfaces guarantee perfect abutment, which improves force. Uneven metal reduce efficiency.
• Heat – NdFeB sinters have a sensitivity to temperature. When it is hot they are weaker, and in frost gain strength (up to a certain limit).

* Lifting capacity testing was performed on a smooth plate of optimal thickness, under perpendicular forces, in contrast under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Moreover, even a small distance {between} the magnet and the plate lowers the load capacity.