MPL 25x10x3 / N38 - lamellar magnet
lamellar magnet
Catalog no 020387
GTIN/EAN: 5906301811862
- length
- 25 mm [±0,1 mm]
- Width
- 10 mm [±0,1 mm]
- Height
- 3 mm [±0,1 mm]
- Weight
- 5.63 g
- Magnetization Direction
- ↑ axial
- Coating
- [NiCuNi] Nickel
How we measure these parameters — certificates and measurements
2.90 zł net / pcs
3.57 zł with VAT (23% VAT) / pcs
bulk discounts:
Need more?Frequently asked questions
How much will a block magnet really hold?
What is the maximum working temperature?
What safety factor should I allow?
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 25x10x3 / N38 - lamellar magnet
Specification / characteristics - MPL 25x10x3 / N38 - lamellar magnet
| properties | values |
|---|---|
| Cat. no. | 020387 |
| GTIN/EAN | 5906301811862 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| length | 25 mm [±0,1 mm] |
| Width | 10 mm [±0,1 mm] |
| Height | 3 mm [±0,1 mm] |
| Weight | 5.63 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 4.14 kg / 40.56 N |
| Magnetic Induction ~ ? | 230.69 mT / 2307 Gs |
| Coating | [NiCuNi] Nickel |
| Manufacturing Tolerance | ±0.1 mm |
Magnetic properties of material N38
| 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
| 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 |
Physical simulation of the product - data
Presented information represent the result of a mathematical analysis. Results are based on models for the material Nd2Fe14B. Actual conditions might slightly differ from theoretical values. Use these data as a supplementary guide during assembly planning.
Table 1: Static force (force vs distance) - interaction chart
MPL 25x10x3 / N38
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg/lbs/g/N) | Risk Status |
|---|---|---|---|
| 0 mm |
2306 Gs
230.6 mT
|
4.14 kg / 9.13 LBS
4140.0 g / 40.6 N
|
warning |
| 1 mm |
2050 Gs
205.0 mT
|
3.27 kg / 7.21 LBS
3272.4 g / 32.1 N
|
warning |
| 2 mm |
1752 Gs
175.2 mT
|
2.39 kg / 5.27 LBS
2388.9 g / 23.4 N
|
warning |
| 3 mm |
1463 Gs
146.3 mT
|
1.67 kg / 3.68 LBS
1667.1 g / 16.4 N
|
low risk |
| 5 mm |
1000 Gs
100.0 mT
|
0.78 kg / 1.72 LBS
779.2 g / 7.6 N
|
low risk |
| 10 mm |
416 Gs
41.6 mT
|
0.13 kg / 0.30 LBS
134.4 g / 1.3 N
|
low risk |
| 15 mm |
200 Gs
20.0 mT
|
0.03 kg / 0.07 LBS
31.0 g / 0.3 N
|
low risk |
| 20 mm |
108 Gs
10.8 mT
|
0.01 kg / 0.02 LBS
9.0 g / 0.1 N
|
low risk |
| 30 mm |
40 Gs
4.0 mT
|
0.00 kg / 0.00 LBS
1.3 g / 0.0 N
|
low risk |
| 50 mm |
10 Gs
1.0 mT
|
0.00 kg / 0.00 LBS
0.1 g / 0.0 N
|
low risk |
Table 2: Sliding force (wall)
MPL 25x10x3 / N38
| Distance (mm) | Friction coefficient | Pull Force (kg/lbs/g/N) |
|---|---|---|
| 0 mm | Stal (~0.2) |
0.83 kg / 1.83 LBS
828.0 g / 8.1 N
|
| 1 mm | Stal (~0.2) |
0.65 kg / 1.44 LBS
654.0 g / 6.4 N
|
| 2 mm | Stal (~0.2) |
0.48 kg / 1.05 LBS
478.0 g / 4.7 N
|
| 3 mm | Stal (~0.2) |
0.33 kg / 0.74 LBS
334.0 g / 3.3 N
|
| 5 mm | Stal (~0.2) |
0.16 kg / 0.34 LBS
156.0 g / 1.5 N
|
| 10 mm | Stal (~0.2) |
0.03 kg / 0.06 LBS
26.0 g / 0.3 N
|
| 15 mm | Stal (~0.2) |
0.01 kg / 0.01 LBS
6.0 g / 0.1 N
|
| 20 mm | Stal (~0.2) |
0.00 kg / 0.00 LBS
2.0 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) - behavior on slippery surfaces
MPL 25x10x3 / N38
| Surface type | Friction coefficient / % Mocy | Max load (kg/lbs/g/N) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
1.24 kg / 2.74 LBS
1242.0 g / 12.2 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
0.83 kg / 1.83 LBS
828.0 g / 8.1 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
0.41 kg / 0.91 LBS
414.0 g / 4.1 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
2.07 kg / 4.56 LBS
2070.0 g / 20.3 N
|
Table 4: Steel thickness (saturation) - power losses
MPL 25x10x3 / N38
| Steel thickness (mm) | % power | Real pull force (kg/lbs/g/N) |
|---|---|---|
| 0.5 mm |
|
0.41 kg / 0.91 LBS
414.0 g / 4.1 N
|
| 1 mm |
|
1.04 kg / 2.28 LBS
1035.0 g / 10.2 N
|
| 2 mm |
|
2.07 kg / 4.56 LBS
2070.0 g / 20.3 N
|
| 3 mm |
|
3.10 kg / 6.85 LBS
3105.0 g / 30.5 N
|
| 5 mm |
|
4.14 kg / 9.13 LBS
4140.0 g / 40.6 N
|
| 10 mm |
|
4.14 kg / 9.13 LBS
4140.0 g / 40.6 N
|
| 11 mm |
|
4.14 kg / 9.13 LBS
4140.0 g / 40.6 N
|
| 12 mm |
|
4.14 kg / 9.13 LBS
4140.0 g / 40.6 N
|
Table 5: Thermal stability (stability) - thermal limit
MPL 25x10x3 / N38
| Ambient temp. (°C) | Power loss | Remaining pull (kg/lbs/g/N) | Status |
|---|---|---|---|
| 20 °C | 0.0% |
4.14 kg / 9.13 LBS
4140.0 g / 40.6 N
|
OK |
| 40 °C | -2.2% |
4.05 kg / 8.93 LBS
4048.9 g / 39.7 N
|
OK |
| 60 °C | -4.4% |
3.96 kg / 8.73 LBS
3957.8 g / 38.8 N
|
|
| 80 °C | -6.6% |
3.87 kg / 8.52 LBS
3866.8 g / 37.9 N
|
|
| 100 °C | -28.8% |
2.95 kg / 6.50 LBS
2947.7 g / 28.9 N
|
Table 6: Magnet-Magnet interaction (attraction) - field collision
MPL 25x10x3 / N38
| Gap (mm) | Attraction (kg/lbs) (N-S) | Shear Force (kg/lbs/g/N) | Repulsion (kg/lbs) (N-N) |
|---|---|---|---|
| 0 mm |
8.20 kg / 18.07 LBS
3 767 Gs
|
1.23 kg / 2.71 LBS
1230 g / 12.1 N
|
N/A |
| 1 mm |
7.38 kg / 16.27 LBS
4 377 Gs
|
1.11 kg / 2.44 LBS
1107 g / 10.9 N
|
6.64 kg / 14.65 LBS
~0 Gs
|
| 2 mm |
6.48 kg / 14.28 LBS
4 101 Gs
|
0.97 kg / 2.14 LBS
972 g / 9.5 N
|
5.83 kg / 12.86 LBS
~0 Gs
|
| 3 mm |
5.58 kg / 12.30 LBS
3 805 Gs
|
0.84 kg / 1.84 LBS
837 g / 8.2 N
|
5.02 kg / 11.07 LBS
~0 Gs
|
| 5 mm |
3.97 kg / 8.74 LBS
3 208 Gs
|
0.59 kg / 1.31 LBS
595 g / 5.8 N
|
3.57 kg / 7.87 LBS
~0 Gs
|
| 10 mm |
1.54 kg / 3.40 LBS
2 001 Gs
|
0.23 kg / 0.51 LBS
231 g / 2.3 N
|
1.39 kg / 3.06 LBS
~0 Gs
|
| 20 mm |
0.27 kg / 0.59 LBS
831 Gs
|
0.04 kg / 0.09 LBS
40 g / 0.4 N
|
0.24 kg / 0.53 LBS
~0 Gs
|
| 50 mm |
0.01 kg / 0.01 LBS
127 Gs
|
0.00 kg / 0.00 LBS
1 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
| 60 mm |
0.00 kg / 0.01 LBS
80 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
54 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
38 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
27 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
20 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
Table 7: Safety (HSE) (implants) - precautionary measures
MPL 25x10x3 / N38
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 6.5 cm |
| Hearing aid | 10 Gs (1.0 mT) | 5.5 cm |
| Mechanical watch | 20 Gs (2.0 mT) | 4.0 cm |
| Mobile device | 40 Gs (4.0 mT) | 3.5 cm |
| Car key | 50 Gs (5.0 mT) | 3.0 cm |
| Payment card | 400 Gs (40.0 mT) | 1.5 cm |
| HDD hard drive | 600 Gs (60.0 mT) | 1.0 cm |
Table 8: Impact energy (cracking risk) - collision effects
MPL 25x10x3 / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
23.96 km/h
(6.66 m/s)
|
0.12 J | |
| 30 mm |
24.40 km/h
(6.78 m/s)
|
0.13 J | |
| 50 mm |
24.40 km/h
(6.78 m/s)
|
0.13 J | |
| 100 mm |
24.41 km/h
(6.78 m/s)
|
0.13 J |
Table 9: Anti-corrosion coating durability
MPL 25x10x3 / 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: Electrical data (Flux)
MPL 25x10x3 / N38
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 5 928 Mx | 59.3 µWb |
| Pc Coefficient | 0.25 | Low (Flat) |
Table 11: Physics of underwater searching
MPL 25x10x3 / N38
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 4.14 kg | Standard |
| Water (riverbed) |
4.74 kg
(+0.60 kg buoyancy gain)
|
+14.5% |
1. Shear force
*Warning: On a vertical surface, the magnet retains only ~20% of its max power.
2. Plate thickness effect
*Thin metal sheet (e.g. computer case) severely limits the holding force.
3. Power loss vs temp
*For N38 material, the critical limit is 80°C.
4. Demagnetization curve and operating point (B-H)
chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.25
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.
Material specification
| 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 |
Other proposals
Advantages and disadvantages of rare earth magnets.
Benefits
- They retain full power for almost ten years – the drop is just ~1% (based on simulations),
- They are extremely resistant to demagnetization induced by external field influence,
- The use of an aesthetic finish of noble metals (nickel, gold, silver) causes the element to look better,
- The surface of neodymium magnets generates a concentrated magnetic field – this is a key feature,
- Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
- Considering the potential of flexible molding and customization to specialized requirements, NdFeB magnets can be created in a wide range of shapes and sizes, which expands the range of possible applications,
- Fundamental importance in modern industrial fields – they serve a role in mass storage devices, electromotive mechanisms, medical equipment, also technologically advanced constructions.
- Thanks to their power density, small magnets offer high operating force, occupying minimum space,
Cons
- At very strong impacts they can break, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
- When exposed to high temperature, neodymium magnets suffer a drop in force. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size and shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
- When exposed to humidity, magnets usually rust. For applications outside, it is recommended to use protective magnets, such as those in rubber or plastics, which prevent oxidation and corrosion.
- We suggest a housing - magnetic holder, due to difficulties in producing nuts inside the magnet and complex forms.
- Health risk to health – tiny shards of magnets pose a threat, if swallowed, which is particularly important in the aspect of protecting the youngest. Furthermore, small components of these products are able to be problematic in diagnostics medical when they are in the body.
- With budget limitations the cost of neodymium magnets is economically unviable,
Lifting parameters
Optimal lifting capacity of a neodymium magnet – what contributes to it?
- using a plate made of mild steel, acting as a circuit closing element
- whose transverse dimension equals approx. 10 mm
- characterized by lack of roughness
- under conditions of no distance (surface-to-surface)
- for force acting at a right angle (pull-off, not shear)
- in temp. approx. 20°C
What influences lifting capacity in practice
- Distance – the presence of foreign body (rust, dirt, air) interrupts the magnetic circuit, which lowers power rapidly (even by 50% at 0.5 mm).
- Pull-off angle – note that the magnet holds strongest perpendicularly. Under shear forces, the holding force drops drastically, often to levels of 20-30% of the maximum value.
- Element thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal restricts the attraction force (the magnet "punches through" it).
- Steel grade – ideal substrate is pure iron steel. Stainless steels may generate lower lifting capacity.
- Plate texture – smooth surfaces ensure maximum contact, which increases field saturation. Uneven metal reduce efficiency.
- Heat – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and in frost gain strength (up to a certain limit).
Holding force was measured on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under parallel forces the lifting capacity is smaller. Moreover, even a slight gap between the magnet and the plate decreases the lifting capacity.
H&S for magnets
Machining danger
Dust produced during grinding of magnets is self-igniting. Avoid drilling into magnets without proper cooling and knowledge.
Safe distance
Equipment safety: Neodymium magnets can ruin payment cards and delicate electronics (pacemakers, medical aids, mechanical watches).
Handling guide
Be careful. Neodymium magnets act from a long distance and connect with huge force, often quicker than you can react.
Physical harm
Big blocks can crush fingers instantly. Do not put your hand between two strong magnets.
Life threat
For implant holders: Powerful magnets affect electronics. Maintain minimum 30 cm distance or request help to handle the magnets.
Sensitization to coating
It is widely known that the nickel plating (the usual finish) is a potent allergen. If your skin reacts to metals, refrain from touching magnets with bare hands or choose encased magnets.
Precision electronics
Be aware: rare earth magnets generate a field that interferes with precision electronics. Keep a safe distance from your mobile, device, and GPS.
Product not for children
NdFeB magnets are not suitable for play. Swallowing multiple magnets may result in them connecting inside the digestive tract, which constitutes a direct threat to life and necessitates immediate surgery.
Heat warning
Avoid heat. NdFeB magnets are susceptible to heat. If you require resistance above 80°C, ask us about HT versions (H, SH, UH).
Risk of cracking
Beware of splinters. Magnets can fracture upon violent connection, launching sharp fragments into the air. Wear goggles.
