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neodymium magnets

We offer blue color magnets Nd2Fe14B - our offer. All magnesy in our store are available for immediate delivery (see the list). Check out the magnet pricing for more details check the magnet price list

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SM 25x350 [2xM8] / N52 - magnetic roller

magnetic separator

catalog number 130355

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diameter Ø

25 mm [±0,1 mm]


350 mm [±0,1 mm]

max. temperature

≤ 80 °C

1057.80 PLN gross price (including VAT) / pcs +

860.00 PLN net price + 23% VAT / pcs

bulk discounts:

need more quantity?

price from 1 pcs
860.00 PLN
1057.80 PLN
price from 3 pcs
817.00 PLN
1004.91 PLN
price from 6 pcs
774.00 PLN
952.02 PLN

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Give us a call tel: +48 888 99 98 98 or get in touch through form on our website. You can check the power as well as the appearance of neodymium magnets in our power calculator force calculator

Orders placed by 2:00 PM will be shipped on the same business day.

Specification: magnetic separator 25x350 [2xM8] / N52

Characteristics: magnetic separator 25x350 [2xM8] / N52
catalog number
production / distribution
Dhit sp. z o.o.
country of origin
Poland / China / Germany
customs code
diameter Ø
25 mm [±0,1 mm]
350 mm [±0,1 mm]
max. temperature ?
≤ 80 °C
0.01 g
execution tolerance
± 0.1 mm
rodzaj materiału
AISI 304 - bezpieczna dla żywności
rodzaj magnesów
NdFeB N52
ilość gwintów
2x [M8] wewnętrzne
obwodowa - 13 nabiegunników
indukcja magnetyczna
~ 9 500 Gauss [±5%]
max. temp. pracy
poniżej ≤ 80°C
grubość rury osłonowej
1 mm

Magnetic properties of the material N52

material characteristics N52
remenance Br [Min. - Max.] ?
remenance Br [Min. - Max.] ?
coercivity bHc ?
coercivity bHc ?
actual internal force iHc
≥ 12
actual internal force iHc
≥ 955
energy density [Min. - Max.]
BH max MGOe
energy density [Min. - Max.]
BH max KJ/m
max. temperature
≤ 80

Physical properties of sintered neodymium magnets Nd2Fe14B

Physical properties of sintered neodymium magnets Nd2Fe14B
Vickers hardness
Curie Temperature TC
312 - 380
Curie Temperature TF
593 - 716
Specific resistance
Bending strength
Compressive strength
Thermal expansion parallel (∥) to orientation (M)
(3-4) x 106
Thermal expansion perpendicular (⊥) to orientation (M)
-(1-3) x 10-6
Young's modulus
1.7 x 104
The magnetic separator, namely the magnetic roller, uses the force of neodymium magnets, placed in a construction made of stainless steel mostly AISI304. As a result, it is possible to efficiently remove ferromagnetic particles from other materials. A fundamental component of its operation is the use of repulsion of N and S poles of neodymium magnets, which enables magnetic substances to be collected. The thickness of the embedded magnet and its structure pitch determine the range and strength of the separator's operation.
Generally speaking, magnetic separators are used to extract ferromagnetic particles. If the cans are made of ferromagnetic materials, the separator will effectively segregate them. However, if the cans are made of non-ferromagnetic materials, such as aluminum, the separator will not effectively segregate them.
Yes, magnetic rollers are used in food production for the elimination of metallic contaminants, such as iron fragments or iron dust. Our rods are constructed from durable acid-resistant steel, AISI 304, approved for use in food.
Magnetic rollers, often called magnetic separators, find application in metal separation, food production as well as waste processing. They help in removing iron dust in the course of the process of separating metals from other materials.
Our magnetic rollers are composed of neodymium magnets placed in a stainless steel tube cylinder made of stainless steel with a wall thickness of 1mm.
Both ends of the magnetic bar will be with M8 threaded openings, enabling simple mounting in machines or magnetic filter drawers. A "blind" version is also possible in manual separators.
In terms of magnetic properties, magnetic bars stand out in terms of flux density, magnetic force lines and the field of the magnetic field. We produce them in materials, N42 as well as N52.
Generally it is believed that the stronger the magnet, the more efficient it is. But, the strength of the magnet's power is based on the height of the used magnet and the quality of the material [N42] or [N52], as well as on the area of use and specific needs. The standard operating temperature of a magnetic bar is 80°C.
When the magnet is thin, the magnetic force lines will be short. By contrast, in the case of a thicker magnet, the force lines will be extended and extend over a greater distance.
For constructing the casings of magnetic separators - rollers, frequently stainless steel is used, particularly types AISI 304, AISI 316, and AISI 316L.
In a salt water contact, AISI 316 steel is highly recommended due to its excellent anti-corrosion properties.
Magnetic bars are characterized by their specific arrangement of poles and their ability to attract magnetic particles directly onto their surface, as opposed to other separators that may utilize more complicated filtration systems.
Technical designations and terms pertaining to magnetic separators include amongst others magnet pitch, polarity, and magnetic induction, as well as the steel type applied.
Magnetic induction for a roller is determined using a teslameter or a gaussmeter with a flat Hall-effect probe, aiming to find the highest magnetic field value near the magnetic pole. The outcome is checked in a value table - the lowest is N30. All designations below N27 or N25 indicate recycling that falls below the standard - they are not suitable.
Neodymium magnetic bars offer a range of benefits such as a very strong magnetic field, the ability to capture even the tiniest metal particles, and durability. On the other hand, among the drawbacks, one can mention higher cost compared to other types of magnets and the need for regular maintenance.
For proper maintenance of neodymium magnetic rollers, it is suggested {to clean them regularly from deposits, avoid extremal temperatures above 80 degrees, and protect them from moisture if the threads are not sealed - in our case. The rollers our rollers have an IP67 waterproof rating, so if they are not sealed, the magnets inside may oxidize and weaken. Magnetic field measurements are suggested to be conducted once every 24 months. Caution should be exercised during use as there is a possibility of finger injury. If the protective tube is only 0.5 mm thick, it can be worn down, which, in turn, may lead to issues with the magnetic rod becoming unsealed and product contamination. The effective operating range of the roller equals its diameter, fi25mm is approximately 25mm active range, while fi32 is about 40mm.

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Advantages and disadvantages of neodymium magnets NdFeB.

In addition to immense power, neodymium magnets have the following advantages:

  • They do not lose strength over time. After approximately 10 years, their strength decreases by only ~1% (theoretically),
  • They protect against demagnetization caused by external magnetic sources extremely well,
  • In other words, thanks to the shiny coating of nickel, gold, or silver, the element acquires an aesthetic appearance,
  • They have very high magnetic induction on the surface of the magnet,
  • Thanks to their high temperature resistance, they can operate (depending on the form) even at temperatures up to 230°C and above...
  • The ability for precise shaping and customization to specific needs – neodymium magnets can be produced in many variants of shapes or sizes, which expands the range of their possible uses.
  • Significant importance in advanced technologically fields – find application in HDD drives, electric motors, medical equipment or very highly developed apparatuses.

Disadvantages of neodymium magnets:

  • They are prone to breaking as they are fragile when subjected to a powerful impact. If the magnets are exposed to impacts, we recommend using magnets in a protective case. The steel housing in the form of a holder protects the magnet from impacts and simultaneously increases its overall strength,
  • High temperatures can reduce the power of neodymium magnets. Typically, after heating above 80°C, most of them experience a permanent reduction in strength (although it is dependent on the form and size). To prevent this, we offer special magnets marked with the symbol [AH], which are highly resistant to high temperatures. They can operate even at temperatures up to 230°C, making them an ideal solution for applications requiring high-temperature operation,
  • Magnets exposed to a humid environment can corrode. Therefore, when using them outdoors, we suggest using waterproof magnets made of rubber, plastic, or other moisture-resistant materials,
  • The use of a cover or a magnetic holder is recommended due to the limited possibilities of manufacturing threads or complex shapes in the magnet
  • Potential hazard to health from tiny fragments of magnets can be dangerous, in case of ingestion, which becomes significant in the context of child safety. It's also worth noting that miniscule components of these devices are able to complicate diagnosis in case of swallowing.

Caution with Neodymium Magnets

Avoid bringing neodymium magnets close to a phone or GPS.

Neodymium magnets are a source of strong magnetic fields that cause interference with magnetometers and compasses used in navigation, as well as internal compasses of smartphones and GPS devices.

Neodymium magnets are the most powerful, most remarkable magnets on the planet, and the surprising force between them can shock you at first.

On our website, you can find information on how to use neodymium magnets. This will help you avoid injuries and prevent damage to the magnets.

  Magnets are not toys, youngest should not play with them.

Not all neodymium magnets are toys, so do not let children play with them. In such a situation, surgery is necessary to remove them. In the worst case scenario, it can result in death.

Neodymium magnets should not be near people with pacemakers.

Neodymium magnets generate strong magnetic fields. As a result, they interfere with the operation of a pacemaker. This is because many of these devices are equipped with a function that deactivates the device in a magnetic field.

The magnet coating is made of nickel, so be cautious if you have an allergy.

Studies show a small percentage of people have allergies to certain metals, including nickel. An allergic reaction often manifests as skin redness and rash. If you have a nickel allergy, try wearing gloves or avoid direct contact with nickel-plated neodymium magnets.

Neodymium magnets can attract to each other, pinch the skin, and cause significant injuries.

Magnets will jump and also clash together within a radius of several to almost 10 cm from each other.

Dust and powder from neodymium magnets are highly flammable.

Avoid drilling or mechanical processing of neodymium magnets. If the magnet is crushed into fine powder or dust, it becomes highly flammable.

Under no circumstances should neodymium magnets be placed near a computer HDD, TV, and wallet.

The strong magnetic field generated by neodymium magnets can damage magnetic media such as floppy disks, video tapes, HDDs, credit cards, magnetic ID cards, cassette tapes, etc. devices. They can also destroy devices like video players, televisions, CRT computer monitors. Remember not to place neodymium magnets close to these electronic devices.

Neodymium magnets are extremely fragile, resulting in their cracking.

Neodymium magnets are fragile and will break if allowed to collide with each other, even from a distance of a few centimeters. Despite being made of metal and coated with a shiny nickel plating, they are not as hard as steel. At the moment of collision between the magnets, small sharp metal fragments can be propelled in various directions at high speed. Eye protection is recommended.

Neodymium magnets can become demagnetized at high temperatures.

Even though magnets have been found to maintain their efficacy up to temperatures of 80°C or 175°F, it's essential to consider that this threshold may fluctuate depending on the magnet's type, configuration, and intended usage.

In order for you to know how powerful neodymium magnets are and why they are so dangerous, read the article - Dangerous very powerful neodymium magnets.

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tel: +48 888 99 98 98