UMH 20x7x35 [M4] / N38 - magnetic holder with hook
magnetic holder with hook
Catalog no 310425
GTIN: 5906301814542
Diameter Ø [±0,1 mm]
20 mm
Height [±0,1 mm]
35 mm
Height [±0,1 mm]
7 mm
Weight
21 g
Magnetization Direction
↑ axial
Load capacity
14.5 kg / 142.2 N
Coating
[NiCuNi] nickel
8.59 ZŁ with VAT / pcs + price for transport
6.98 ZŁ net + 23% VAT / pcs
bulk discounts:
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Magnetic properties of material N38
Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C
Shopping tips
Strengths and weaknesses of neodymium magnets.
In addition to their magnetic capacity, neodymium magnets provide the following advantages:
- They virtually do not lose power, because even after 10 years the decline in efficiency is only ~1% (according to literature),
- Neodymium magnets are distinguished by extremely resistant to loss of magnetic properties caused by magnetic disturbances,
- By applying a lustrous coating of silver, the element presents an elegant look,
- Magnets possess impressive magnetic induction on the outer layer,
- Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
- Due to the option of accurate forming and adaptation to individualized solutions, neodymium magnets can be produced in a variety of forms and dimensions, which expands the range of possible applications,
- Significant place in future technologies – they are utilized in hard drives, electromotive mechanisms, precision medical tools, also multitasking production systems.
- Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in tiny dimensions, which makes them useful in compact constructions
Disadvantages of NdFeB magnets:
- Susceptibility to cracking is one of their disadvantages. Upon intense impact they can fracture. We recommend keeping them in a steel housing, which not only protects them against impacts but also increases their durability
- We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we suggest our specialized [AH] magnets, which work effectively even at 230°C.
- They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
- Due to limitations in realizing threads and complex shapes in magnets, we propose using cover - magnetic mechanism.
- Potential hazard related to microscopic parts of magnets pose a threat, if swallowed, which gains importance in the context of child safety. Additionally, tiny parts of these magnets are able to complicate diagnosis medical in case of swallowing.
- High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities
Highest magnetic holding force – what it depends on?
The force parameter is a theoretical maximum value performed under standard conditions:
- using a base made of low-carbon steel, acting as a circuit closing element
- whose thickness is min. 10 mm
- with a surface perfectly flat
- under conditions of ideal adhesion (surface-to-surface)
- under axial force vector (90-degree angle)
- at conditions approx. 20°C
Determinants of lifting force in real conditions
Please note that the magnet holding will differ influenced by the following factors, in order of importance:
- Clearance – existence of any layer (paint, tape, air) interrupts the magnetic circuit, which reduces capacity steeply (even by 50% at 0.5 mm).
- Load vector – maximum parameter is available only during perpendicular pulling. The resistance to sliding of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
- Steel thickness – too thin sheet does not accept the full field, causing part of the power to be wasted into the air.
- Chemical composition of the base – mild steel gives the best results. Alloy admixtures lower magnetic permeability and lifting capacity.
- Plate texture – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces reduce efficiency.
- Temperature – temperature increase results in weakening of induction. Check the thermal limit for a given model.
* Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, however under shearing force the holding force is lower. Additionally, even a slight gap {between} the magnet and the plate lowers the holding force.
Safety rules for work with neodymium magnets
Pacemakers
Medical warning: Strong magnets can turn off heart devices and defibrillators. Do not approach if you have medical devices.
Crushing risk
Pinching hazard: The pulling power is so great that it can result in blood blisters, pinching, and even bone fractures. Use thick gloves.
Do not overheat magnets
Do not overheat. NdFeB magnets are susceptible to heat. If you require resistance above 80°C, inquire about HT versions (H, SH, UH).
Allergy Warning
A percentage of the population experience a contact allergy to Ni, which is the standard coating for neodymium magnets. Prolonged contact may cause a rash. It is best to use protective gloves.
Fragile material
Neodymium magnets are ceramic materials, meaning they are prone to chipping. Impact of two magnets leads to them cracking into small pieces.
Product not for children
Absolutely store magnets away from children. Ingestion danger is significant, and the effects of magnets connecting inside the body are fatal.
Handling guide
Handle with care. Rare earth magnets attract from a distance and snap with huge force, often faster than you can react.
Fire risk
Fire hazard: Neodymium dust is explosive. Do not process magnets in home conditions as this may cause fire.
Magnetic media
Powerful magnetic fields can corrupt files on credit cards, HDDs, and other magnetic media. Keep a distance of at least 10 cm.
Impact on smartphones
An intense magnetic field negatively affects the functioning of compasses in phones and GPS navigation. Maintain magnets near a smartphone to avoid damaging the sensors.
Attention!
Learn more about risks in the article: Safety of working with magnets.
