UMP 97x40 [M8+M10] GW F300 kg / N38 - search holder

Pros and cons of rare earth magnets.

Besides their tremendous strength, neodymium magnets offer the following advantages:

• Their power is maintained, and after around ten years it drops only by ~1% (according to research),
• They are resistant to demagnetization induced by external disturbances,
• A magnet with a shiny gold surface has better aesthetics,
• Magnets are characterized by huge magnetic induction on the working surface,
• These magnets tolerate extreme temperatures, often exceeding 230°C, when properly designed (in relation to build),
• Considering the option of flexible molding and customization to custom needs, NdFeB magnets can be modeled in a wide range of geometric configurations, which expands the range of possible applications,
• Universal use in innovative solutions – they find application in data components, electric drive systems, advanced medical instruments, also technologically advanced constructions.
• Thanks to concentrated force, small magnets offer high operating force, with minimal size,

What to avoid - cons of neodymium magnets: weaknesses and usage proposals

• Brittleness is one of their disadvantages. Upon strong impact they can break. We recommend keeping them in a strong case, which not only protects them against impacts but also raises their durability
• When exposed to high temperature, neodymium magnets suffer a drop in power. Often, when the temperature exceeds 80°C, their power 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
• Due to the susceptibility of magnets to corrosion in a humid environment, we advise using waterproof magnets made of rubber, plastic or other material immune to moisture, when using outdoors
• We recommend cover - magnetic mount, due to difficulties in realizing threads inside the magnet and complex forms.
• Potential hazard to health – tiny shards of magnets can be dangerous, in case of ingestion, which becomes key in the context of child safety. It is also worth noting that small components of these magnets can disrupt the diagnostic process medical after entering the body.
• With budget limitations the cost of neodymium magnets is economically unviable,

Highest magnetic holding force – what affects it?

Holding force of 380 kg is a theoretical maximum value performed under the following configuration:

• with the use of a sheet made of special test steel, guaranteeing maximum field concentration
• whose thickness equals approx. 10 mm
• with an ideally smooth touching surface
• with total lack of distance (no impurities)
• for force acting at a right angle (pull-off, not shear)
• in temp. approx. 20°C

Lifting capacity in real conditions – factors

In practice, the real power is determined by several key aspects, ranked from most significant:

• Air gap (between the magnet and the metal), as even a tiny clearance (e.g. 0.5 mm) leads to a drastic drop in lifting capacity by up to 50% (this also applies to varnish, corrosion or dirt).
• Force direction – 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.
• Metal thickness – thin material does not allow full use of the magnet. Part of the magnetic field penetrates through instead of generating force.
• Steel grade – ideal substrate is high-permeability steel. Cast iron may have worse magnetic properties.
• Plate texture – ground elements guarantee perfect abutment, which increases field saturation. Rough surfaces weaken the grip.
• Temperature – heating the magnet results in weakening of induction. It is worth remembering the thermal limit for a given model.

* Lifting capacity was measured by applying a smooth steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, in contrast under shearing force the lifting capacity is smaller. In addition, even a slight gap {between} the magnet’s surface and the plate decreases the holding force.