UMS 16x6.5x3.5x5 / N38 - conical magnetic holder

Pros and cons of NdFeB magnets.

Besides their tremendous magnetic power, neodymium magnets offer the following advantages:

• Their strength is durable, and after around ten years it drops only by ~1% (according to research),
• They feature excellent resistance to magnetism drop when exposed to external magnetic sources,
• A magnet with a metallic nickel surface has an effective appearance,
• Magnets are characterized by very high magnetic induction on the working surface,
• Due to their durability and thermal resistance, neodymium magnets can operate (depending on the form) even at high temperatures reaching 230°C or more...
• Thanks to freedom in shaping and the capacity to modify to client solutions,
• Fundamental importance in advanced technology sectors – they serve a role in magnetic memories, motor assemblies, medical devices, and other advanced devices.
• Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Problematic aspects of neodymium magnets and ways of using them

• They are fragile upon heavy 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 lose their strength at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
• When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
• We recommend a housing - magnetic mount, due to difficulties in creating threads inside the magnet and complex shapes.
• Health risk resulting from small fragments of magnets can be dangerous, if swallowed, which gains importance in the context of child safety. It is also worth noting that small components of these devices are able to complicate diagnosis medical in case of swallowing.
• Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Maximum lifting capacity of the magnet – what it depends on?

The specified lifting capacity represents the peak performance, measured under laboratory conditions, namely:

• using a sheet made of low-carbon steel, serving as a circuit closing element
• with a thickness minimum 10 mm
• with a surface perfectly flat
• without the slightest insulating layer between the magnet and steel
• under axial force vector (90-degree angle)
• at room temperature

Lifting capacity in real conditions – factors

It is worth knowing that the working load may be lower depending on the following factors, in order of importance:

• Distance (between the magnet and the metal), as even a very small clearance (e.g. 0.5 mm) can cause a reduction in lifting capacity by up to 50% (this also applies to varnish, rust or dirt).
• Force direction – remember that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
• Material type – the best choice is pure iron steel. Stainless steels may attract less.
• Base smoothness – the more even the plate, the better the adhesion and higher the lifting capacity. Roughness acts like micro-gaps.
• Thermal factor – high temperature reduces pulling force. Too high temperature can permanently demagnetize the magnet.

* Lifting capacity was assessed using a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular detachment force, however under shearing force the load capacity is reduced by as much as 5 times. In addition, even a slight gap {between} the magnet and the plate decreases the holding force.