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SM 28x250 [2xM8] / N52 - magnetic separator

magnetic separator

Catalog no 130522

Diameter Ø
28 mm [±1 mm]
Height
250 mm [±1 mm]
Weight
1204.22 g
Magnetic Flux
~ 8 500 Gauss [±5%]

How we measure these parameters — certificates and measurements

see technical data »

650.00 zł net / pcs

799.50 zł with VAT (23% VAT) / pcs

price for transport

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Frequently asked questions

Which rod should I choose for fine contamination?
For particles below 0.5 mm — a Ø32 mm rod in grade N52, with surface induction of about 10,000 Gs. A Ø25 rod in grade N42 gives about 6,500 Gs and is chosen for contamination above 1 mm: bolts, washers, pieces of wire.
Which rod pitch should I choose?
The narrow pitch, 40 mm centre to centre, for fine free-flowing fractions — it gives denser coverage of the cross-section. The wide pitch, 50 mm, for granulates and for damp, greasy or sticky materials, where a narrow pitch risks the material bridging above the rods.
Why does efficiency drop after a few weeks of operation?
Almost always because the separator has not been cleaned. The layer of captured particles shields the field, and further particles settle on that layer rather than on the rod surface, where the gradient is far stronger. The magnets themselves do not weaken at that rate.

Guides from the knowledge base

Want to talk magnets?

Call us now +48 888 99 98 98 alternatively let us know using contact form the contact section.
Specifications and structure of a neodymium magnet can be estimated using our power calculator.

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Technical - SM 28x250 [2xM8] / N52 - magnetic separator

Specification / characteristics - SM 28x250 [2xM8] / N52 - magnetic separator

properties
properties values
Cat. no. 130522
Production/Distribution Dhit sp. z o.o.
ul. Zielona 14 05-850 Ożarów Mazowiecki PL
Country of origin Poland / China / Germany
Customs code 85059029
Diameter Ø 28 mm [±1 mm]
Height 250 mm [±1 mm]
Weight 1204.22 g
Material Type Stainless steel AISI 304 / A2
Magnetic Flux ~ 8 500 Gauss [±5%]
Size/Mount Quantity M8x2
Polarity circumferential - 9 poles
Casing Tube Thickness 1 mm
Manufacturing Tolerance ±1 mm

Magnetic properties of material N52

Specification / characteristics SM 28x250 [2xM8] / N52 - magnetic separator
properties values units
remenance Br [min. - max.] ? 14.2-14.7 kGs
remenance Br [min. - max.] ? 1420-1470 mT
coercivity bHc ? 10.8-12.5 kOe
coercivity bHc ? 860-995 kA/m
actual internal force iHc ≥ 12 kOe
actual internal force iHc ≥ 955 kA/m
energy density [min. - max.] ? 48-53 BH max MGOe
energy density [min. - max.] ? 380-422 BH max KJ/m
max. temperature ? ≤ 80 °C

Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C

Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C
properties values units
Vickers hardness ≥550 Hv
Density ≥7.4 g/cm3
Curie Temperature TC 310 °C
Curie Temperature TF 590 °F
Specific resistance 150 μΩ⋅cm
Bending strength 250 MPa
Compressive strength 1000~1100 MPa
Thermal expansion parallel (∥) to orientation (M) (3-4) x 10-6 °C-1
Thermal expansion perpendicular (⊥) to orientation (M) -(1-3) x 10-6 °C-1
Young's modulus 1.7 x 104 kg/mm²

Table 1: Rod construction
SM 28x250 [2xM8] / N52

Parameter Value Description / Unit
Diameter (Ø) 28 mm
Total length 250 mm (L)
Active length 214 mm
Section count 9 modules
Dead zone 36 mm (2x 18mm starter)
Weight (est.) ~1170 g
Active area 188 cm² (Area)
Housing material AISI 304 1.4301 (Inox)
Surface finish Ra < 0.8 µm Polished
Temp. class 80°C Standard (N)
Force loss (at max °C) -12.8% Reversible loss (physics)
Force (calculated) 22.7 kg (theor.)
Induction (surface) ~8 500 Gauss (Max)
Max T = 80°C. Construction data for M8/M10 thread series.

Chart 2: Field profile (9 sections)

Simulation: 9 magnetic modules (pitch 23 mm).

Chart 3: Temperature performance

Technical and environmental data

Chemical composition

iron (Fe) 64% – 68%
neodymium (Nd) 29% – 32%
boron (B) 1.1% – 1.2%
dysprosium (Dy) 0.5% – 2.0%
coating (Ni-Cu-Ni) < 0.05%

Sustainability

recyclability (EoL) 100%
recycled raw materials ~10% (pre-cons)
carbon footprint low / zredukowany
waste code (EWC) 16 02 16
Safety card (GPSR)
responsible entity
Dhit sp. z o.o.
ul. Kościuszki 6A, 05-850 Ożarów Mazowiecki
tel: +48 22 499 98 98 | e-mail: bok@dhit.pl
batch number/type
id: 130522-2026
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It is the "heart" of every magnetic filter used in industry for cleaning raw materials. Its task is separation (separation) of metal filings from the transported material. Thanks to the use of strong neodymium magnets, the rod catches even metallic dust.
The rod consists of a cover tube made of high-quality acid-resistant steel (AISI 304 or 316). The core is a precise magnetic system generating high induction (Gauss). Thanks to this, the rod is durable, hygienic, and easy to keep clean.
Due to the high power of the magnet, direct removal of filings can be troublesome and time-consuming. You can use compressed air or special non-magnetic strippers (rings). For easier operation, it is worth considering ordering a rod in a version with a cleaning sleeve.
Magnetic induction measured in Gauss (Gs) determines the density of magnetic flux on the rod surface. For basic machine protection against pieces of iron, standard power is sufficient. For the food and precision industry, we recommend the highest induction parameters.
Yes, as a manufacturer, we make rods of any length and diameter (standard is dia 25mm and 32mm). The rod end is strictly adapted to the fastening system in your device. We ensure fast realization of special orders and technical advice.

Advantages as well as disadvantages of rare earth magnets.

Advantages

In addition to their magnetic efficiency, neodymium magnets provide the following advantages:
  • They retain attractive force for almost ten years – the drop is just ~1% (based on simulations),
  • Magnets perfectly defend themselves against loss of magnetization caused by foreign field sources,
  • The use of an aesthetic layer of noble metals (nickel, gold, silver) causes the element to be more visually attractive,
  • The surface of neodymium magnets generates a unique magnetic field – this is a distinguishing feature,
  • Through (adequate) combination of ingredients, they can achieve high thermal strength, allowing for functioning at temperatures approaching 230°C and above...
  • Possibility of custom modeling as well as adjusting to specific applications,
  • Significant place in high-tech industry – they serve a role in magnetic memories, drive modules, medical devices, also modern systems.
  • Thanks to efficiency per cm³, small magnets offer high operating force, in miniature format,

Disadvantages

What to avoid - cons of neodymium magnets: weaknesses and usage proposals
  • They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only protects the magnet but also improves its resistance to damage
  • Neodymium magnets lose their power under the influence of heating. As soon as 80°C is exceeded, many of them start losing their force. Therefore, we recommend our special magnets marked [AH], which maintain durability even at temperatures up to 230°C
  • When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which secure oxidation as well as corrosion.
  • Limited ability of producing nuts in the magnet and complicated forms - recommended is casing - mounting mechanism.
  • Health risk related to microscopic parts of magnets can be dangerous, in case of ingestion, which gains importance in the context of child health protection. It is also worth noting that small components of these devices can complicate diagnosis medical after entering the body.
  • High unit price – neodymium magnets cost more than other types of magnets (e.g. ferrite), which increases costs of application in large quantities

Holding force characteristics

Maximum holding power of the magnet – what contributes to it?

Information about lifting capacity is the result of a measurement for the most favorable conditions, including:
  • using a sheet made of high-permeability steel, acting as a ideal flux conductor
  • with a cross-section of at least 10 mm
  • with an ground touching surface
  • without any clearance between the magnet and steel
  • for force acting at a right angle (in the magnet axis)
  • in temp. approx. 20°C

Magnet lifting force in use – key factors

Real force impacted by working environment parameters, such as (from priority):
  • Space between surfaces – every millimeter of separation (caused e.g. by veneer or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
  • Angle of force application – maximum parameter is obtained only during perpendicular pulling. The resistance to sliding of the magnet along the plate is usually several times smaller (approx. 1/5 of the lifting capacity).
  • Base massiveness – too thin plate does not close the flux, causing part of the power to be escaped into the air.
  • Material composition – not every steel reacts the same. High carbon content worsen the attraction effect.
  • Surface quality – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Unevenness creates an air distance.
  • Thermal environment – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

Lifting capacity testing was performed on plates with a smooth surface of suitable thickness, under perpendicular forces, however under shearing force the holding force is lower. Additionally, even a minimal clearance between the magnet and the plate reduces the load capacity.

Safe handling of NdFeB magnets
Keep away from electronics

Note: rare earth magnets generate a field that interferes with sensitive sensors. Maintain a separation from your mobile, tablet, and GPS.

Permanent damage

Regular neodymium magnets (grade N) lose magnetization when the temperature goes above 80°C. Damage is permanent.

Magnet fragility

Neodymium magnets are sintered ceramics, meaning they are prone to chipping. Clashing of two magnets leads to them cracking into small pieces.

Product not for children

Absolutely store magnets out of reach of children. Risk of swallowing is significant, and the effects of magnets connecting inside the body are tragic.

Dust explosion hazard

Fire hazard: Rare earth powder is highly flammable. Do not process magnets without safety gear as this risks ignition.

Metal Allergy

Medical facts indicate that nickel (the usual finish) is a strong allergen. If your skin reacts to metals, refrain from direct skin contact and choose versions in plastic housing.

Life threat

For implant holders: Powerful magnets disrupt electronics. Maintain minimum 30 cm distance or request help to handle the magnets.

Bone fractures

Mind your fingers. Two large magnets will snap together immediately with a force of massive weight, crushing anything in their path. Be careful!

Protect data

Powerful magnetic fields can corrupt files on credit cards, HDDs, and other magnetic media. Stay away of at least 10 cm.

Powerful field

Before use, read the rules. Sudden snapping can destroy the magnet or hurt your hand. Think ahead.

Warning! Need more info? Read our article: Are neodymium magnets dangerous?