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neodymium magnets

We offer blue color magnetic Nd2Fe14B - our store's offer. All "magnets" in our store are in stock for immediate delivery (check the list). Check out the magnet pricing for more details check the magnet price list

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SM 25x200 [2xM8] / N42 - magnetic roller

magnetic separator

catalog number 130291

GTIN: 5906301812845

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diameter Ø

25 mm [±0,1 mm]

height

200 mm [±0,1 mm]

max. temperature

≤ 80 °C

541.20 gross price (including VAT) / pcs +

440.00 ZŁ net price + 23% VAT / pcs

bulk discounts:

need more quantity?

price from 1 pcs
440.00 ZŁ
541.20 ZŁ
price from 5 pcs
418.00 ZŁ
514.14 ZŁ
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396.00 ZŁ
487.08 ZŁ

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Give us a call tel: +48 22 499 98 98 or get in touch via form on the contact page. You can check the mass and the appearance of neodymium magnets in our power calculator magnetic calculator

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

Specification: magnetic separator 25x200 [2xM8] / N42

Characteristics: magnetic separator 25x200 [2xM8] / N42
Properties
Values
catalog number
130291
production / distribution
Dhit sp. z o.o.
country of origin
Poland / China / Germany
customs code
85059029
diameter Ø
25 mm [±0,1 mm]
height
200 mm [±0,1 mm]
max. temperature ?
≤ 80 °C
weight
0.01 g
execution tolerance
± 0.1 mm
rodzaj materiału
AISI 304 - bezpieczna dla żywności
rodzaj magnesów
NdFeB N42
ilość gwintów
2x [M8] wewnętrzne
biegunowość
obwodowa - 7 nabiegunników
indukcja magnetyczna
~ 6 500 Gauss [±5%]
max. temp. pracy
poniżej ≤ 80°C
grubość rury osłonowej
1 mm

Magnetic properties of the material N42

material characteristics N42
Properties
Values
units
remenance Br [Min. - Max.] ?
12.9-13.2
kGs
remenance Br [Min. - Max.] ?
1290-1320
T
coercivity bHc ?
10.8-12.0
kOe
coercivity bHc ?
860-955
kA/m
actual internal force iHc
≥ 12
kOe
actual internal force iHc
≥ 955
kA/m
energy density [Min. - Max.]
40-42
BH max MGOe
energy density [Min. - Max.]
318-334
BH max KJ/m
max. temperature
≤ 80
°C

Physical properties of sintered neodymium magnets Nd2Fe14B

Physical properties of sintered neodymium magnets Nd2Fe14B
Properties
Values
units
Vickers hardness
≥550
Hv
Density
≥7.4
g/cm3
Curie Temperature TC
312 - 380
°C
Curie Temperature TF
593 - 716
°F
Specific resistance
150
μΩ⋅Cm
Bending strength
250
Mpa
Compressive strength
1000~1100
Mpa
Thermal expansion parallel (∥) to orientation (M)
(3-4) x 106
°C-1
Thermal expansion perpendicular (⊥) to orientation (M)
-(1-3) x 10-6
°C-1
Young's modulus
1.7 x 104
kg/mm²
The main mechanism of the magnetic separator is the use of neodymium magnets, which are welded in a casing made of stainless steel mostly AISI304. In this way, it is possible to efficiently separate ferromagnetic particles from different substances. 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 attracted. The thickness of the magnet and its structure pitch affect the range and strength of the separator's operation.
Generally speaking, magnetic separators are used to segregate ferromagnetic elements. 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 be able to separate them.
Yes, magnetic rollers are used in the food sector to clear metallic contaminants, for example iron fragments or iron dust. Our rollers are constructed from durable acid-resistant steel, EN 1.4301, intended for contact with food.
Magnetic rollers, otherwise magnetic separators, are employed in food production, metal separation as well as waste processing. They help in eliminating iron dust during the process of separating metals from other wastes.
Our magnetic rollers are composed of neodymium magnets embedded in a stainless steel tube casing made of stainless steel with a wall thickness of 1mm.
Both ends of the magnetic bar can be with M8 threaded openings, which enables simple mounting in machines or magnetic filter drawers. A "blind" version is also possible in manual separators.
In terms of magnetic properties, magnetic bars differ 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.
Usually it is believed that the greater the magnet's power, the more effective. However, the strength of the magnet's power depends 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 anticipated needs. The standard operating temperature of a magnetic bar is 80°C.
In the case where the magnet is thin, the magnetic force lines are more compressed. On the other hand, when the magnet is thick, the force lines will be longer and extend over a greater distance.
For constructing the casings of magnetic separators - rollers, usually stainless steel is utilized, particularly types AISI 304, AISI 316, and AISI 316L.
In a salt water environment, AISI 316 steel exhibits the best resistance thanks to its outstanding anti-corrosion properties.
Magnetic rollers stand out for their unique configuration of poles and their capability to attract magnetic particles directly onto their surface, as opposed to other separators that may utilize more complicated filtration systems.
Technical designations and terms related to magnetic separators include among others magnet pitch, polarity, and magnetic induction, as well as the type of steel used.
Magnetic induction for a magnet on a roller is measured using a teslameter or a gaussmeter with a flat Hall-effect probe, seeking the highest magnetic field value near the magnetic pole. The result is verified in a value table - the lowest is N30. All designations less than N27 or N25 indicate recycling that doesn't meet the standard - they are not suitable.
Neodymium magnetic bars offer many advantages, including excellent separation efficiency, strong magnetic field, and durability. On the other hand, among the drawbacks, one can mention the need for regular cleaning, higher cost, and potential installation challenges.
To properly maintain of neodymium magnetic rollers, it is recommended cleaning after each use, avoiding temperatures above 80 degrees. The rollers feature waterproofing IP67, so if they are not sealed, the magnets inside can oxidize and lose their power. Testing of the rollers should be carried out every two years. Caution should be taken during use, as there is a risk of finger injury. If the protective tube is only 0.5 mm thick, it may wear out, which in turn could lead to problems with the magnetic rod seal and product contamination. The range of the roller is equal to its diameter: fi25mm gives an active range of about 25mm, while fi32 gives an active range of about 40mm.
A magnetic roller is a magnetic separator made from a neodymium magnet enclosed in a cylindrical stainless steel housing, used for separating ferromagnetic contaminants from raw materials. They are used in the food industry, recycling, and plastic processing, where the removal of iron metals and iron filings is essential.

Product suggestions

Advantages and disadvantages of neodymium magnets NdFeB.

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

  • They do not lose their strength (of the magnet). After about 10 years, their power decreases by only ~1% (theoretically),
  • They are exceptionally resistant to demagnetization caused by an external magnetic field,
  • In other words, thanks to the glossy nickel, gold, or silver finish, the element gains an aesthetic appearance,
  • They exhibit extremely high magnetic induction on the surface of the magnet,
  • By using an appropriate combination of materials, they can achieve significant thermal resistance, allowing them to operate at temperatures up to 230°C and above...
  • Due to the option of accurate forming or adaptation to individual needs – neodymium magnets can be produced in various forms and dimensions, which amplifies their universality in usage.
  • Key role in advanced technologically fields – find application in hard drives, electric motors, medical apparatus or very highly developed apparatuses.

Disadvantages of neodymium magnets:

  • They are prone to breaking as they are fragile when subjected to a strong impact. If the magnets are exposed to impacts, it is suggested using magnets in a metal holder. The steel housing in the form of a holder protects the magnet from impacts and simultaneously increases its overall strength,
  • Magnets lose their strength due to exposure to high temperatures. In most cases, when the temperature exceeds 80°C, these magnets experience permanent loss in strength (although it is worth noting that this is dependent on the shape and size of the magnet). To avoid this problem, we offer special magnets marked with the [AH] symbol, which exhibit high temperature resistance. They can operate even at temperatures as high as 230°C or more,
  • They rust in a humid environment - during outdoor use, we recommend using waterproof magnets, such as those made of rubber or plastic,
  • 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
  • Health risk associated with microscopic parts of magnets are risky, when accidentally ingested, which is particularly important in the aspect of protecting young children. It's also worth noting that miniscule components of these devices are able to complicate diagnosis in case of swallowing.

Handle Neodymium Magnets Carefully

Neodymium Magnets can attract to each other, pinch the skin, and cause significant swellings.

If joining of neodymium magnets is not under control, then they may crumble and crack. You can't move them to each other. At a distance less than 10 cm you should have them extremely firmly.

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

Remember that neodymium magnets are not toys. Do not allow children to play with them. In the case of swallowing multiple magnets simultaneously, they can attract to each other through the intestinal walls. In the worst case scenario, this can lead to death.

Keep neodymium magnets away from people with pacemakers.

Neodymium magnets generate strong magnetic fields. As a result, they interfere with the operation of a pacemaker. This happens because such devices have a function to deactivate them in a magnetic field.

Avoid bringing neodymium magnets close to a phone or GPS.

Neodymium magnets are a source of intense 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 over 10 times stronger than ferrite magnets (the ones in speakers), and their power can surprise you.

To handle magnets properly, it is best to familiarize yourself with our information beforehand. This will help you avoid significant harm to your body and the magnets themselves.

The magnet coating contains nickel, so be cautious if you have a nickel allergy.

Studies clearly indicate a small percentage of people who suffer from metal allergies such as nickel. An allergic reaction often manifests as skin redness and rash. If you have a nickel allergy, you can try wearing gloves or simply avoid direct contact with nickel-plated neodymium magnets.

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

Strong magnetic fields emitted by neodymium magnets can damage magnetic storage media such as floppy disks, credit cards, magnetic ID cards, cassette tapes, video tapes, or other devices. They can also damage televisions, VCRs, computer monitors, and CRT displays. You should especially avoid placing neodymium magnets near electronic devices.

Neodymium magnets can demagnetize at high temperatures.

While Neodymium magnets can demagnetize at high temperatures, it's important to note that the extent of this effect can vary based on factors such as the magnet's material, shape, and intended application.

Dust and powder from neodymium magnets are flammable.

Do not attempt to drill into neodymium magnets. Mechanical processing is also not recommended. If the magnet is crushed into fine powder or dust, it becomes highly flammable.

Neodymium magnetic are extremely delicate, they easily crack as well as can become damaged.

Neodymium magnetic are extremely fragile, and by joining them in an uncontrolled manner, they will break. Neodymium magnets are made of metal and coated with a shiny nickel surface, but they are not as hard as steel. In the event of a collision between two magnets, there may be a scattering of fragments in different directions. Protecting your eyes is crucial in such a situation.

To show why neodymium magnets are so dangerous, read the article - How dangerous are very strong neodymium magnets?.

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e-mail: bok@dhit.pl

tel: +48 888 99 98 98