AM ucho [M8] - magnetic accessories

Advantages and disadvantages of neodymium magnets.

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:

• Their strength is maintained, and after around ten years it drops only by ~1% (theoretically),
• Magnets very well resist against loss of magnetization caused by foreign field sources,
• In other words, due to the smooth finish of gold, the element is aesthetically pleasing,
• Neodymium magnets create maximum magnetic induction on a small area, which ensures high operational effectiveness,
• Neodymium magnets are characterized by very high magnetic induction on the magnet surface and are able to act (depending on the form) even at a temperature of 230°C or more...
• Thanks to flexibility in constructing and the ability to customize to individual projects,
• Universal use in modern technologies – they serve a role in data components, electric drive systems, advanced medical instruments, as well as industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which makes them useful in miniature devices

Cons of neodymium magnets and ways of using them

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also increases its resistance to damage
• Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures 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 those in rubber or plastics, which secure oxidation and corrosion.
• Due to limitations in realizing nuts and complicated forms in magnets, we recommend using casing - magnetic holder.
• Potential hazard resulting from small fragments of magnets can be dangerous, if swallowed, which is particularly important in the aspect of protecting the youngest. It is also worth noting that small elements of these devices are able to disrupt the diagnostic process medical when they are in the body.
• Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Maximum magnetic pulling force – what contributes to it?

Breakaway force was defined for the most favorable conditions, taking into account:

• with the contact of a sheet made of special test steel, guaranteeing full magnetic saturation
• with a thickness minimum 10 mm
• with an ideally smooth touching surface
• without any air gap between the magnet and steel
• for force applied at a right angle (pull-off, not shear)
• at conditions approx. 20°C

Determinants of practical lifting force of a magnet

Bear in mind that the working load will differ influenced by the following factors, in order of importance:

• Gap (between the magnet and the metal), since even a very small distance (e.g. 0.5 mm) can cause a drastic drop in lifting capacity by up to 50% (this also applies to varnish, corrosion or debris).
• Force direction – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
• Substrate thickness – to utilize 100% power, the steel must be sufficiently thick. Paper-thin metal limits the lifting capacity (the magnet "punches through" it).
• Material composition – not every steel reacts the same. High carbon content weaken the attraction effect.
• Surface structure – the smoother and more polished the surface, the better the adhesion and stronger the hold. Roughness acts like micro-gaps.
• Thermal factor – high temperature reduces magnetic field. Exceeding the limit temperature can permanently demagnetize the magnet.

* Lifting capacity was determined using a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, however under shearing force the holding force is lower. Moreover, even a slight gap {between} the magnet and the plate reduces the lifting capacity.