MPL 40x5x3 / N38 - lamellar magnet

lamellar magnet

Catalog no 020402

GTIN/EAN: 5906301811916

Load capacity 7.33 kg / 71.91 N Magnetic Induction 348.83 mT / 3488 Gs
length
40 mm [±0,1 mm]
Width
5 mm [±0,1 mm]
Height
3 mm [±0,1 mm]
Weight
4.5 g
Magnetization Direction
↑ axial
Coating
[NiCuNi] Nickel

5.41net / pcs

6.65 zł with VAT (23% VAT) / pcs

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Net
Gross
price from 1 pcs
5.41 zł
6.65 zł
price from 150 pcs
5.09 zł
6.26 zł
price from 500 pcs
4.76 zł
5.86 zł

Engineering report for this magnet

Full PDF analysis: pull and shear force, effect of distance, temperature and plate thickness, safety distances and the demagnetization curve.

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Technical of the product - MPL 40x5x3 / N38 - lamellar magnet

Specification / characteristics - MPL 40x5x3 / N38 - lamellar magnet

properties
properties values
Cat. no. 020402
GTIN/EAN 5906301811916
Production/Distribution Dhit sp. z o.o.
ul. Zielona 14 05-850 Ożarów Mazowiecki PL
Country of origin Poland / China / Germany
Customs code 85059029
length 40 mm [±0,1 mm]
Width 5 mm [±0,1 mm]
Height 3 mm [±0,1 mm]
Weight 4.5 g
Magnetization Direction ↑ axial
Load capacity ~ ? 7.33 kg / 71.91 N
Magnetic Induction ~ ? 348.83 mT / 3488 Gs
Coating [NiCuNi] Nickel
Manufacturing Tolerance ±0.1 mm

Magnetic properties of material N38

Specification / characteristics MPL 40x5x3 / N38 - lamellar magnet
properties values units
remenance Br [min. - max.] ? 12.2-12.6 kGs
remenance Br [min. - max.] ? 1220-1260 mT
coercivity bHc ? 10.8-11.5 kOe
coercivity bHc ? 860-915 kA/m
actual internal force iHc ≥ 12 kOe
actual internal force iHc ≥ 955 kA/m
energy density [min. - max.] ? 36-38 BH max MGOe
energy density [min. - max.] ? 287-303 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 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 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

Engineering analysis of the magnet - data

Presented values constitute the result of a mathematical simulation. Results were calculated on models for the material Nd2Fe14B. Operational performance may differ. Please consider these data as a supplementary guide when designing systems.

Table 1: Static force (pull vs distance) - characteristics
MPL 40x5x3 / N38

Distance (mm) Induction (Gauss) / mT Pull Force (kg/lbs/g/N) Risk Status
0 mm 3485 Gs
348.5 mT
7.33 kg / 16.16 LBS
7330.0 g / 71.9 N
strong
1 mm 2529 Gs
252.9 mT
3.86 kg / 8.51 LBS
3859.9 g / 37.9 N
strong
2 mm 1741 Gs
174.1 mT
1.83 kg / 4.03 LBS
1829.7 g / 17.9 N
weak grip
3 mm 1217 Gs
121.7 mT
0.89 kg / 1.97 LBS
893.7 g / 8.8 N
weak grip
5 mm 664 Gs
66.4 mT
0.27 kg / 0.59 LBS
265.9 g / 2.6 N
weak grip
10 mm 235 Gs
23.5 mT
0.03 kg / 0.07 LBS
33.5 g / 0.3 N
weak grip
15 mm 116 Gs
11.6 mT
0.01 kg / 0.02 LBS
8.2 g / 0.1 N
weak grip
20 mm 67 Gs
6.7 mT
0.00 kg / 0.01 LBS
2.7 g / 0.0 N
weak grip
30 mm 27 Gs
2.7 mT
0.00 kg / 0.00 LBS
0.5 g / 0.0 N
weak grip
50 mm 8 Gs
0.8 mT
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
weak grip

Table 2: Sliding hold (vertical surface)
MPL 40x5x3 / N38

Distance (mm) Friction coefficient Pull Force (kg/lbs/g/N)
0 mm Stal (~0.2) 1.47 kg / 3.23 LBS
1466.0 g / 14.4 N
1 mm Stal (~0.2) 0.77 kg / 1.70 LBS
772.0 g / 7.6 N
2 mm Stal (~0.2) 0.37 kg / 0.81 LBS
366.0 g / 3.6 N
3 mm Stal (~0.2) 0.18 kg / 0.39 LBS
178.0 g / 1.7 N
5 mm Stal (~0.2) 0.05 kg / 0.12 LBS
54.0 g / 0.5 N
10 mm Stal (~0.2) 0.01 kg / 0.01 LBS
6.0 g / 0.1 N
15 mm Stal (~0.2) 0.00 kg / 0.00 LBS
2.0 g / 0.0 N
20 mm Stal (~0.2) 0.00 kg / 0.00 LBS
0.0 g / 0.0 N
30 mm Stal (~0.2) 0.00 kg / 0.00 LBS
0.0 g / 0.0 N
50 mm Stal (~0.2) 0.00 kg / 0.00 LBS
0.0 g / 0.0 N

Table 3: Vertical assembly (shearing) - vertical pull
MPL 40x5x3 / N38

Surface type Friction coefficient / % Mocy Max load (kg/lbs/g/N)
Raw steel
µ = 0.3 30% Nominalnej Siły
2.20 kg / 4.85 LBS
2199.0 g / 21.6 N
Painted steel (standard)
µ = 0.2 20% Nominalnej Siły
1.47 kg / 3.23 LBS
1466.0 g / 14.4 N
Oily/slippery steel
µ = 0.1 10% Nominalnej Siły
0.73 kg / 1.62 LBS
733.0 g / 7.2 N
Magnet with anti-slip rubber
µ = 0.5 50% Nominalnej Siły
3.67 kg / 8.08 LBS
3665.0 g / 36.0 N

Table 4: Material efficiency (saturation) - sheet metal selection
MPL 40x5x3 / N38

Steel thickness (mm) % power Real pull force (kg/lbs/g/N)
0.5 mm
10%
0.73 kg / 1.62 LBS
733.0 g / 7.2 N
1 mm
25%
1.83 kg / 4.04 LBS
1832.5 g / 18.0 N
2 mm
50%
3.67 kg / 8.08 LBS
3665.0 g / 36.0 N
3 mm
75%
5.50 kg / 12.12 LBS
5497.5 g / 53.9 N
5 mm
100%
7.33 kg / 16.16 LBS
7330.0 g / 71.9 N
10 mm
100%
7.33 kg / 16.16 LBS
7330.0 g / 71.9 N
11 mm
100%
7.33 kg / 16.16 LBS
7330.0 g / 71.9 N
12 mm
100%
7.33 kg / 16.16 LBS
7330.0 g / 71.9 N

Table 5: Thermal stability (stability) - power drop
MPL 40x5x3 / N38

Ambient temp. (°C) Power loss Remaining pull (kg/lbs/g/N) Status
20 °C 0.0% 7.33 kg / 16.16 LBS
7330.0 g / 71.9 N
OK
40 °C -2.2% 7.17 kg / 15.80 LBS
7168.7 g / 70.3 N
OK
60 °C -4.4% 7.01 kg / 15.45 LBS
7007.5 g / 68.7 N
80 °C -6.6% 6.85 kg / 15.09 LBS
6846.2 g / 67.2 N
100 °C -28.8% 5.22 kg / 11.51 LBS
5219.0 g / 51.2 N

Table 6: Two magnets (repulsion) - field collision
MPL 40x5x3 / N38

Gap (mm) Attraction (kg/lbs) (N-S) Lateral Force (kg/lbs/g/N) Repulsion (kg/lbs) (N-N)
0 mm 14.97 kg / 33.01 LBS
4 697 Gs
2.25 kg / 4.95 LBS
2246 g / 22.0 N
N/A
1 mm 11.16 kg / 24.61 LBS
6 017 Gs
1.67 kg / 3.69 LBS
1674 g / 16.4 N
10.04 kg / 22.15 LBS
~0 Gs
2 mm 7.88 kg / 17.38 LBS
5 058 Gs
1.18 kg / 2.61 LBS
1183 g / 11.6 N
7.10 kg / 15.64 LBS
~0 Gs
3 mm 5.44 kg / 11.99 LBS
4 201 Gs
0.82 kg / 1.80 LBS
816 g / 8.0 N
4.90 kg / 10.79 LBS
~0 Gs
5 mm 2.59 kg / 5.71 LBS
2 899 Gs
0.39 kg / 0.86 LBS
389 g / 3.8 N
2.33 kg / 5.14 LBS
~0 Gs
10 mm 0.54 kg / 1.20 LBS
1 328 Gs
0.08 kg / 0.18 LBS
81 g / 0.8 N
0.49 kg / 1.08 LBS
~0 Gs
20 mm 0.07 kg / 0.15 LBS
471 Gs
0.01 kg / 0.02 LBS
10 g / 0.1 N
0.06 kg / 0.14 LBS
~0 Gs
50 mm 0.00 kg / 0.00 LBS
83 Gs
0.00 kg / 0.00 LBS
0 g / 0.0 N
0.00 kg / 0.00 LBS
~0 Gs
60 mm 0.00 kg / 0.00 LBS
55 Gs
0.00 kg / 0.00 LBS
0 g / 0.0 N
0.00 kg / 0.00 LBS
~0 Gs
70 mm 0.00 kg / 0.00 LBS
38 Gs
0.00 kg / 0.00 LBS
0 g / 0.0 N
0.00 kg / 0.00 LBS
~0 Gs
80 mm 0.00 kg / 0.00 LBS
27 Gs
0.00 kg / 0.00 LBS
0 g / 0.0 N
0.00 kg / 0.00 LBS
~0 Gs
90 mm 0.00 kg / 0.00 LBS
20 Gs
0.00 kg / 0.00 LBS
0 g / 0.0 N
0.00 kg / 0.00 LBS
~0 Gs
100 mm 0.00 kg / 0.00 LBS
15 Gs
0.00 kg / 0.00 LBS
0 g / 0.0 N
0.00 kg / 0.00 LBS
~0 Gs

Table 7: Hazards (implants) - warnings
MPL 40x5x3 / N38

Object / Device Limit (Gauss) / mT Safe distance
Pacemaker 5 Gs (0.5 mT) 6.0 cm
Hearing aid 10 Gs (1.0 mT) 4.5 cm
Mechanical watch 20 Gs (2.0 mT) 3.5 cm
Mobile device 40 Gs (4.0 mT) 3.0 cm
Remote 50 Gs (5.0 mT) 2.5 cm
Payment card 400 Gs (40.0 mT) 1.0 cm
HDD hard drive 600 Gs (60.0 mT) 1.0 cm

Table 8: Impact energy (kinetic energy) - warning
MPL 40x5x3 / N38

Start from (mm) Speed (km/h) Energy (J) Predicted outcome
10 mm 25.03 km/h
(6.95 m/s)
0.11 J
30 mm 25.17 km/h
(6.99 m/s)
0.11 J
50 mm 25.16 km/h
(6.99 m/s)
0.11 J
100 mm 25.17 km/h
(6.99 m/s)
0.11 J

Table 9: Anti-corrosion coating durability
MPL 40x5x3 / N38

Technical parameter Value / Description
Coating type [NiCuNi] Nickel
Layer structure Nickel - Copper - Nickel
Layer thickness 10-20 µm
Salt spray test (SST) ? 24 h
Recommended environment Indoors only (dry)

Table 10: Construction data (Flux)
MPL 40x5x3 / N38

Parameter Value SI Unit / Description
Magnetic Flux 5 123 Mx 51.2 µWb
Pc Coefficient 0.27 Low (Flat)

Table 11: Physics of underwater searching
MPL 40x5x3 / N38

Environment Effective steel pull Effect
Air (land) 7.33 kg Standard
Water (riverbed) 8.39 kg
(+1.06 kg buoyancy gain)
+14.5%
Warning: This magnet has a standard nickel coating. After use in water, it must be dried and maintained immediately, otherwise it will rust!

1. Vertical hold

*Caution: On a vertical wall, the magnet retains merely approx. 20-30% of its nominal pull.

2. Steel thickness impact

*Thin metal sheet (e.g. computer case) severely limits the holding force.

3. Heat tolerance

*For N38 grade, the safety limit is 80°C.

4. Demagnetization curve and operating point (B-H)

chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.27

The chart above illustrates the magnetic characteristics of the material within the second quadrant of the hysteresis loop. The solid red line represents the demagnetization curve (material potential), while the dashed blue line is the load line based on the magnet's geometry. The Pc (Permeance Coefficient), also known as the load line slope, is a dimensionless value that describes the relationship between the magnet's shape and its magnetic stability. The intersection of these two lines (the black dot) is the operating point — it determines the actual magnetic flux density generated by the magnet in this specific configuration. A higher Pc value means the magnet is more 'slender' (tall relative to its area), resulting in a higher operating point and better resistance to irreversible demagnetization caused by external fields or temperature. A value of 0.42 is relatively low (typical for flat magnets), meaning the operating point is closer to the 'knee' of the curve — caution is advised when operating at temperatures near the maximum limit to avoid strength loss.

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%

Environmental data

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: 020402-2026
Measurement Calculator

Magnet pull force


Magnetic Field

Other offers

This product is a very powerful magnet in the shape of a plate made of NdFeB material, which, with dimensions of 40x5x3 mm and a weight of 4.5 g, guarantees premium class connection. This magnetic block with a force of 71.91 N is ready for shipment in 24h, allowing for rapid realization of your project. Additionally, its Ni-Cu-Ni coating protects it against corrosion in standard operating conditions, giving it an aesthetic appearance.
Separating block magnets requires a technique based on sliding (moving one relative to the other), rather than forceful pulling apart. To separate the MPL 40x5x3 / N38 model, firmly slide one magnet over the edge of the other until the attraction force decreases. We recommend extreme caution, because after separation, the magnets may want to violently snap back together, which threatens pinching the skin. Never use metal tools for prying, as the brittle NdFeB material may chip and damage your eyes.
Plate magnets MPL 40x5x3 / N38 are the foundation for many industrial devices, such as magnetic separators and linear motors. They work great as fasteners under tiles, wood, or glass. Customers often choose this model for workshop organization on strips and for advanced DIY and modeling projects, where precision and power count.
Cyanoacrylate glues (super glue type) are good only for small magnets; for larger plates, we recommend resins. For lighter applications or mounting on smooth surfaces, branded foam tape (e.g., 3M VHB) will work, provided the surface is perfectly degreased. Avoid chemically aggressive glues or hot glue, which can demagnetize neodymium (above 80°C).
Standardly, the MPL 40x5x3 / N38 model is magnetized through the thickness (dimension 3 mm), which means that the N and S poles are located on its largest, flat surfaces. Thanks to this, it works best when "sticking" to sheet metal or another magnet with a large surface area. Such a pole arrangement ensures maximum holding capacity when pressing against the sheet, creating a closed magnetic circuit.
This model is characterized by dimensions 40x5x3 mm, which, at a weight of 4.5 g, makes it an element with high energy density. The key parameter here is the lifting capacity amounting to approximately 7.33 kg (force ~71.91 N), which, with such a flat shape, proves the high power of the material. The product meets the standards for N38 grade magnets.

Advantages as well as disadvantages of Nd2Fe14B magnets.

Advantages

Besides their exceptional strength, neodymium magnets offer the following advantages:
  • Their magnetic field is durable, and after around ten years it decreases only by ~1% (according to research),
  • They maintain their magnetic properties even under external field action,
  • In other words, due to the shiny finish of nickel, the element gains visual value,
  • Magnets are characterized by maximum magnetic induction on the outer side,
  • Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
  • Thanks to flexibility in constructing and the ability to customize to specific needs,
  • Significant place in high-tech industry – they are commonly used in computer drives, motor assemblies, advanced medical instruments, and technologically advanced constructions.
  • Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which allows their use in compact constructions

Weaknesses

Disadvantages of neodymium magnets:
  • They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only protects the magnet but also improves its resistance to damage
  • Neodymium magnets decrease 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 stability even at temperatures up to 230°C
  • They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
  • We suggest cover - magnetic mechanism, due to difficulties in producing threads inside the magnet and complicated shapes.
  • Health risk resulting from small fragments of magnets are risky, if swallowed, which becomes key in the context of child safety. It is also worth noting that small elements of these devices are able to complicate diagnosis medical after entering the body.
  • Due to neodymium price, their price is higher than average,

Lifting parameters

Optimal lifting capacity of a neodymium magnetwhat contributes to it?

Holding force of 7.33 kg is a theoretical maximum value performed under the following configuration:
  • on a block made of structural steel, effectively closing the magnetic field
  • whose transverse dimension reaches at least 10 mm
  • with a surface cleaned and smooth
  • without the slightest clearance between the magnet and steel
  • under axial force direction (90-degree angle)
  • at standard ambient temperature

Lifting capacity in real conditions – factors

Real force impacted by specific conditions, such as (from priority):
  • Space between surfaces – even a fraction of a millimeter of distance (caused e.g. by veneer or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
  • Loading method – declared lifting capacity refers to detachment vertically. When attempting to slide, the magnet exhibits much less (often approx. 20-30% of nominal force).
  • Element thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet limits the attraction force (the magnet "punches through" it).
  • Metal type – different alloys reacts the same. Alloy additives worsen the attraction effect.
  • Surface condition – ground elements guarantee perfect abutment, which increases force. Rough surfaces reduce efficiency.
  • Temperature – temperature increase results in weakening of induction. It is worth remembering the maximum operating temperature for a given model.

Holding force was checked on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. In addition, even a minimal clearance between the magnet and the plate lowers the holding force.

Precautions when working with neodymium magnets
Safe distance

Intense magnetic fields can corrupt files on credit cards, hard drives, and storage devices. Stay away of at least 10 cm.

Product not for children

These products are not toys. Eating a few magnets may result in them attracting across intestines, which poses a direct threat to life and requires urgent medical intervention.

Shattering risk

Beware of splinters. Magnets can explode upon violent connection, launching shards into the air. Wear goggles.

Dust is flammable

Combustion risk: Rare earth powder is highly flammable. Avoid machining magnets in home conditions as this may cause fire.

Compass and GPS

A strong magnetic field negatively affects the functioning of compasses in phones and GPS navigation. Maintain magnets close to a device to avoid breaking the sensors.

Handling guide

Handle magnets consciously. Their immense force can surprise even professionals. Stay alert and do not underestimate their power.

Health Danger

Life threat: Neodymium magnets can turn off pacemakers and defibrillators. Stay away if you have medical devices.

Warning for allergy sufferers

Warning for allergy sufferers: The Ni-Cu-Ni coating consists of nickel. If redness occurs, immediately stop handling magnets and wear gloves.

Maximum temperature

Avoid heat. NdFeB magnets are sensitive to temperature. If you require resistance above 80°C, look for special high-temperature series (H, SH, UH).

Pinching danger

Protect your hands. Two powerful magnets will join instantly with a force of massive weight, destroying everything in their path. Exercise extreme caution!

Warning! Details about risks in the article: Safety of working with magnets.