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 magnetic properties for around 10 years – the drop is just ~1% (in theory),
• They are resistant to demagnetization induced by presence of other magnetic fields,
• The use of an elegant finish of noble metals (nickel, gold, silver) causes the element to look better,
• Magnets exhibit huge magnetic induction on the active area,
• Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for action at temperatures reaching 230°C and above...
• Thanks to modularity in shaping and the capacity to modify to complex applications,
• Significant place in innovative solutions – they are utilized in HDD drives, brushless drives, medical equipment, and technologically advanced constructions.
• Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Drawbacks and weaknesses of neodymium magnets: weaknesses and usage proposals

• To avoid cracks under impact, we suggest using special steel holders. Such a solution secures 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 strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
• When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• Limited ability of making threads in the magnet and complicated shapes - recommended is a housing - magnetic holder.
• Possible danger resulting from small fragments of magnets can be dangerous, when accidentally swallowed, which becomes key in the aspect of protecting the youngest. Additionally, small elements of these devices are able to disrupt the diagnostic process medical in case of swallowing.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

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

The load parameter shown concerns the maximum value, obtained under optimal environment, specifically:

• with the contact of a yoke made of low-carbon steel, ensuring full magnetic saturation
• whose transverse dimension reaches at least 10 mm
• with a plane cleaned and smooth
• with total lack of distance (no coatings)
• for force applied at a right angle (pull-off, not shear)
• at room temperature

Determinants of practical lifting force of a magnet

Effective lifting capacity is affected by working environment parameters, such as (from priority):

• Space between surfaces – every millimeter of separation (caused e.g. by veneer or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
• Pull-off angle – remember that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the nominal value.
• Substrate thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
• Material composition – not every steel attracts identically. High carbon content worsen the interaction with the magnet.
• Surface finish – full contact is possible only on smooth steel. Rough texture create air cushions, reducing force.
• Thermal environment – temperature increase causes a temporary drop of force. Check the maximum operating temperature for a given model.

* Lifting capacity was measured by applying a polished steel plate of suitable thickness (min. 20 mm), under vertically applied force, however under parallel forces the load capacity is reduced by as much as 5 times. In addition, even a small distance {between} the magnet’s surface and the plate reduces the holding force.