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SM 25x300 [2xM8] / N42 - magnetic separator

magnetic separator

Catalog no 130295

GTIN/EAN: 5906301812883

5.00
Diameter Ø
25 mm [±1 mm]
Height
300 mm [±1 mm]
Weight
1160 g
Magnetic Flux
~ 6 500 Gauss [±5%]

How we measure these parameters — certificates and measurements

technical specifications »

680.00 zł net / pcs

836.40 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 25x300 [2xM8] / N42 - magnetic separator

Specification / characteristics - SM 25x300 [2xM8] / N42 - magnetic separator

properties
properties values
Cat. no. 130295
GTIN/EAN 5906301812883
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 25 mm [±1 mm]
Height 300 mm [±1 mm]
Weight 1160 g
Material Type Stainless steel AISI 304 / A2
Magnetic Flux ~ 6 500 Gauss [±5%]
Size/Mount Quantity 2xM8
Polarity circumferential - 11 poles
Casing Tube Thickness 1 mm
Manufacturing Tolerance ±1 mm

Magnetic properties of material N42

Specification / characteristics SM 25x300 [2xM8] / N42 - magnetic separator
properties values units
Remanence Br ? 12.9-13.2 kGs
Remanence Br ? 1290-1320 mT
Coercivity bHc ? 10.8-12.0 kOe
Coercivity bHc ? 860-955 kA/m
Intrinsic coercivity iHc ≥ 12 kOe
Intrinsic coercivity iHc ≥ 955 kA/m
Energy product BHmax ? 40-42 BH max MGOe
Energy product BHmax ? 318-334 BH max KJ/m
Maximum working 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 25x300 [2xM8] / N42

Parameter Value Description / Unit
Diameter (Ø) 25 mm
Total length 300 mm (L)
Active length 264 mm
Section count 11 modules
Dead zone 36 mm (2x 18mm starter)
Weight (est.) ~1119 g
Active area 207 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) 10.6 kg (theor.)
Induction (surface) ~6 500 Gauss (Max)
Max T = 80°C. Construction data for M8/M10 thread series.

Chart 2: Field profile (11 sections)

Simulation: 11 magnetic modules (pitch 23 mm).

Chart 3: Temperature performance

Technical and environmental data

Elemental analysis

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: 130295-2026
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This product serves to effectively catch ferromagnetic contaminants from bulk and liquid products. Its task is separation (separation) of metal filings from the transported material. High magnetic induction on the surface allows catching the finest iron particles.
The construction relies on a sealed, welded stainless steel housing, polished smooth. Inside there is a stack of strong neodymium magnets arranged in a special configuration (magnetic circuit). Such construction ensures full resistance to corrosion, water, oils, and acids.
Metal filings stick to the surface very strongly, so cleaning requires strength or cleverness. We recommend sticking packing tape to the cluster of filings and tearing it off together with the contaminants. 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). You can choose a mounting method consistent with your technical design. Contact us for a quote on a non-standard dimension.

Pros as well as cons of rare earth magnets.

Advantages

Apart from their superior holding force, neodymium magnets have these key benefits:
  • Their magnetic field remains stable, and after approximately ten years it decreases only by ~1% (theoretically),
  • They retain their magnetic properties even under strong external field,
  • A magnet with a shiny nickel surface has better aesthetics,
  • Magnetic induction on the working part of the magnet remains extremely intense,
  • Neodymium magnets are characterized by very high magnetic induction on the magnet surface and can work (depending on the shape) even at a temperature of 230°C or more...
  • Thanks to the possibility of accurate forming and customization to specialized projects, magnetic components can be modeled in a broad palette of shapes and sizes, which expands the range of possible applications,
  • Versatile presence in modern technologies – they are utilized in magnetic memories, electric drive systems, advanced medical instruments, and industrial machines.
  • Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in compact dimensions, which makes them useful in miniature devices

Cons

Disadvantages of NdFeB magnets:
  • They are fragile upon too strong impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only shields the magnet but also increases 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
  • 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, in case of application outdoors
  • We suggest a housing - magnetic holder, due to difficulties in producing threads inside the magnet and complex shapes.
  • Health risk related to microscopic parts of magnets can be dangerous, in case of ingestion, which is particularly important in the context of child health protection. Furthermore, small components of these devices can disrupt the diagnostic process medical when they are in the body.
  • Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Holding force characteristics

Maximum magnetic pulling force – what contributes to it?

Holding force of 0.00 kg is a measurement result executed under standard conditions:
  • on a block made of mild steel, optimally conducting the magnetic flux
  • whose thickness reaches at least 10 mm
  • characterized by smoothness
  • with total lack of distance (no impurities)
  • during detachment in a direction perpendicular to the mounting surface
  • in stable room temperature

Determinants of lifting force in real conditions

It is worth knowing that the magnet holding will differ depending on elements below, starting with the most relevant:
  • Air gap (between the magnet and the plate), because even a very small distance (e.g. 0.5 mm) leads to a reduction in force by up to 50% (this also applies to varnish, corrosion or dirt).
  • Pull-off angle – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the nominal value.
  • Plate thickness – insufficiently thick sheet causes magnetic saturation, causing part of the power to be wasted to the other side.
  • Plate material – mild steel attracts best. Higher carbon content reduce magnetic permeability and holding force.
  • Plate texture – smooth surfaces ensure maximum contact, which improves force. Uneven metal weaken the grip.
  • Thermal factor – high temperature weakens pulling force. Too high temperature can permanently demagnetize the magnet.

Lifting capacity testing was conducted on a smooth plate of suitable thickness, under perpendicular forces, whereas under parallel forces the load capacity is reduced by as much as fivefold. Moreover, even a minimal clearance between the magnet’s surface and the plate decreases the lifting capacity.

Safety rules for work with NdFeB magnets
Avoid contact if allergic

Some people suffer from a contact allergy to nickel, which is the typical protective layer for neodymium magnets. Extended handling might lead to dermatitis. We strongly advise wear safety gloves.

Product not for children

Only for adults. Tiny parts pose a choking risk, leading to severe trauma. Store away from children and animals.

Risk of cracking

Despite metallic appearance, the material is delicate and not impact-resistant. Do not hit, as the magnet may crumble into hazardous fragments.

Do not drill into magnets

Machining of NdFeB material carries a risk of fire hazard. Neodymium dust reacts violently with oxygen and is difficult to extinguish.

GPS and phone interference

A strong magnetic field negatively affects the functioning of compasses in smartphones and navigation systems. Maintain magnets close to a smartphone to avoid damaging the sensors.

Heat sensitivity

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

Do not underestimate power

Handle magnets with awareness. Their immense force can shock even experienced users. Be vigilant and respect their force.

Cards and drives

Equipment safety: Strong magnets can damage payment cards and delicate electronics (heart implants, hearing aids, timepieces).

Hand protection

Large magnets can smash fingers instantly. Under no circumstances put your hand between two attracting surfaces.

ICD Warning

Individuals with a heart stimulator have to maintain an safe separation from magnets. The magnetism can disrupt the operation of the implant.

Important! Looking for details? Read our article: Are neodymium magnets dangerous?