UMGW 60x30x15 [M10] GW / N38 - magnetic holder internal thread

Advantages and disadvantages of neodymium magnets NdFeB.

In addition to their pulling strength, neodymium magnets provide the following advantages:

• They do not lose their magnetism, even after around ten years – the loss of strength is only ~1% (theoretically),
• They protect against demagnetization induced by external magnetic influence effectively,
• Thanks to the glossy finish and nickel coating, they have an visually attractive appearance,
• They possess significant magnetic force measurable at the magnet’s surface,
• Thanks to their high temperature resistance, they can operate (depending on the shape) even at temperatures up to 230°C or more,
• With the option for customized forming and personalized design, these magnets can be produced in numerous shapes and sizes, greatly improving design adaptation,
• Important function in modern technologies – they are used in computer drives, rotating machines, clinical machines or even other advanced devices,
• Compactness – despite their small size, they deliver powerful magnetism, making them ideal for precision applications

Disadvantages of NdFeB magnets:

• They may fracture when subjected to a heavy impact. If the magnets are exposed to shocks, we recommend in a steel housing. The steel housing, in the form of a holder, protects the magnet from damage , and at the same time strengthens its overall resistance,
• Magnets lose pulling force when exposed to temperatures exceeding 80°C. In most cases, this leads to irreversible magnetic decay (influenced by the magnet’s dimensions). To address this, we provide [AH] models with superior thermal resistance, able to operate even at 230°C or more,
• Due to corrosion risk in humid conditions, it is common to use sealed magnets made of rubber for outdoor use,
• The use of a protective casing or external holder is recommended, since machining threads in neodymium magnets is risky,
• Health risk from tiny pieces may arise, in case of ingestion, which is important in the health of young users. Additionally, small elements from these devices might disrupt scanning after being swallowed,
• Due to expensive raw materials, their cost is considerably higher,

Magnetic strength at its maximum – what affects it?

The given strength of the magnet means the optimal strength, assessed under optimal conditions, that is:

• using a steel plate with low carbon content, acting as a magnetic circuit closure
• having a thickness of no less than 10 millimeters
• with a refined outer layer
• with zero air gap
• in a perpendicular direction of force
• in normal thermal conditions

Determinants of practical lifting force of a magnet

In practice, the holding capacity of a magnet is affected by these factors, from crucial to less important:

• Air gap between the magnet and the plate, since even a very small distance (e.g. 0.5 mm) causes a drop in lifting force of up to 50%.
• Direction of applied force, because the maximum lifting capacity is achieved under perpendicular application. The force required to slide the magnet along the plate is usually several times lower.
• Thickness of the plate, as a plate that is too thin causes part of the magnetic flux not to be used and to remain wasted in the air.
• Material of the plate, because higher carbon content lowers holding force, while higher iron content increases it. The best choice is steel with high magnetic permeability and high saturation induction.
• Surface of the plate, because the more smooth and polished it is, the better the contact and consequently the greater the magnetic saturation.
• Operating temperature, since all permanent magnets have a negative temperature coefficient. This means that at high temperatures they are weaker, while at sub-zero temperatures they become slightly stronger.

* Lifting capacity was measured using a smooth steel plate of suitable thickness (min. 20 mm), under perpendicular pulling force, whereas under shearing force the holding force is lower. Moreover, even a slight gap {between} the magnet and the plate lowers the load capacity.