UMGW 48x24x11.5 [M8] GW / N38 - magnetic holder internal thread

Pros and cons of NdFeB magnets.

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

• Their strength is durable, and after around 10 years it decreases only by ~1% (theoretically),
• They are extremely resistant to demagnetization induced by external field influence,
• A magnet with a smooth nickel surface has an effective appearance,
• They show high magnetic induction at the operating surface, which increases their power,
• These magnets tolerate high temperatures, often exceeding 230°C, when properly designed (in relation to form),
• Possibility of precise creating as well as adjusting to complex requirements,
• Significant place in high-tech industry – they serve a role in HDD drives, electric drive systems, diagnostic systems, as well as industrial machines.
• Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in small dimensions, which enables their usage in small systems

Characteristics of disadvantages of neodymium magnets: application proposals

• To avoid cracks upon strong impacts, we suggest using special steel housings. Such a solution protects the magnet and simultaneously increases its durability.
• We warn that neodymium magnets can reduce their strength at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
• They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
• We recommend casing - magnetic mechanism, due to difficulties in creating nuts inside the magnet and complex forms.
• Health risk related to microscopic parts of magnets are risky, in case of ingestion, which is particularly important in the context of child health protection. Furthermore, small components of these magnets can disrupt the diagnostic process medical in case of swallowing.
• High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which can limit application in large quantities

Highest magnetic holding force – what affects it?

Information about lifting capacity is the result of a measurement for ideal contact conditions, assuming:

• on a block made of structural steel, optimally conducting the magnetic flux
• whose transverse dimension reaches at least 10 mm
• characterized by smoothness
• without the slightest clearance between the magnet and steel
• for force acting at a right angle (pull-off, not shear)
• at temperature room level

Practical lifting capacity: influencing factors

During everyday use, the actual lifting capacity depends on many variables, presented from the most important:

• Gap between magnet and steel – every millimeter of distance (caused e.g. by veneer or unevenness) drastically reduces the pulling force, often by half at just 0.5 mm.
• Force direction – note that the magnet holds strongest perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the nominal value.
• Steel thickness – too thin steel does not close the flux, causing part of the power to be escaped into the air.
• Metal type – not every steel attracts identically. High carbon content worsen the attraction effect.
• Surface finish – ideal contact is possible only on polished steel. Rough texture create air cushions, weakening the magnet.
• Thermal environment – temperature increase causes a temporary drop of induction. Check the thermal limit for a given model.

* Lifting capacity was determined by applying a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, whereas under shearing force the holding force is lower. Moreover, even a small distance {between} the magnet’s surface and the plate decreases the lifting capacity.