MPL 40x20x4x2[7/3.5] / N38 - lamellar magnet
lamellar magnet
Catalog no 020159
GTIN/EAN: 5906301811657
length
40 mm [±0,1 mm]
Width
20 mm [±0,1 mm]
Height
4 mm [±0,1 mm]
Weight
24 g
Magnetization Direction
↑ axial
Load capacity
7.52 kg / 73.80 N
Magnetic Induction
168.28 mT / 1683 Gs
Coating
[NiCuNi] Nickel
17.96 ZŁ with VAT / pcs + price for transport
14.60 ZŁ net + 23% VAT / pcs
bulk discounts:
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Product card - MPL 40x20x4x2[7/3.5] / N38 - lamellar magnet
Specification / characteristics - MPL 40x20x4x2[7/3.5] / N38 - lamellar magnet
| properties | values |
|---|---|
| Cat. no. | 020159 |
| GTIN/EAN | 5906301811657 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| length | 40 mm [±0,1 mm] |
| Width | 20 mm [±0,1 mm] |
| Height | 4 mm [±0,1 mm] |
| Weight | 24 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 7.52 kg / 73.80 N |
| Magnetic Induction ~ ? | 168.28 mT / 1683 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 | 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 |
Technical modeling of the product - data
These values represent the outcome of a engineering analysis. Results rely on algorithms for the class Nd2Fe14B. Operational performance may differ. Use these data as a reference point when designing systems.
Table 1: Static force (force vs gap) - characteristics
MPL 40x20x4x2[7/3.5] / N38
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg/lbs/g/N) | Risk Status |
|---|---|---|---|
| 0 mm |
1683 Gs
168.3 mT
|
7.52 kg / 16.58 LBS
7520.0 g / 73.8 N
|
medium risk |
| 1 mm |
1613 Gs
161.3 mT
|
6.91 kg / 15.24 LBS
6913.8 g / 67.8 N
|
medium risk |
| 2 mm |
1524 Gs
152.4 mT
|
6.17 kg / 13.61 LBS
6172.9 g / 60.6 N
|
medium risk |
| 3 mm |
1423 Gs
142.3 mT
|
5.38 kg / 11.86 LBS
5379.4 g / 52.8 N
|
medium risk |
| 5 mm |
1207 Gs
120.7 mT
|
3.87 kg / 8.53 LBS
3869.8 g / 38.0 N
|
medium risk |
| 10 mm |
744 Gs
74.4 mT
|
1.47 kg / 3.24 LBS
1469.3 g / 14.4 N
|
weak grip |
| 15 mm |
455 Gs
45.5 mT
|
0.55 kg / 1.21 LBS
550.7 g / 5.4 N
|
weak grip |
| 20 mm |
288 Gs
28.8 mT
|
0.22 kg / 0.49 LBS
220.3 g / 2.2 N
|
weak grip |
| 30 mm |
129 Gs
12.9 mT
|
0.04 kg / 0.10 LBS
44.4 g / 0.4 N
|
weak grip |
| 50 mm |
38 Gs
3.8 mT
|
0.00 kg / 0.01 LBS
3.8 g / 0.0 N
|
weak grip |
Table 2: Slippage hold (vertical surface)
MPL 40x20x4x2[7/3.5] / N38
| Distance (mm) | Friction coefficient | Pull Force (kg/lbs/g/N) |
|---|---|---|
| 0 mm | Stal (~0.2) |
1.50 kg / 3.32 LBS
1504.0 g / 14.8 N
|
| 1 mm | Stal (~0.2) |
1.38 kg / 3.05 LBS
1382.0 g / 13.6 N
|
| 2 mm | Stal (~0.2) |
1.23 kg / 2.72 LBS
1234.0 g / 12.1 N
|
| 3 mm | Stal (~0.2) |
1.08 kg / 2.37 LBS
1076.0 g / 10.6 N
|
| 5 mm | Stal (~0.2) |
0.77 kg / 1.71 LBS
774.0 g / 7.6 N
|
| 10 mm | Stal (~0.2) |
0.29 kg / 0.65 LBS
294.0 g / 2.9 N
|
| 15 mm | Stal (~0.2) |
0.11 kg / 0.24 LBS
110.0 g / 1.1 N
|
| 20 mm | Stal (~0.2) |
0.04 kg / 0.10 LBS
44.0 g / 0.4 N
|
| 30 mm | Stal (~0.2) |
0.01 kg / 0.02 LBS
8.0 g / 0.1 N
|
| 50 mm | Stal (~0.2) |
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
Table 3: Vertical assembly (sliding) - behavior on slippery surfaces
MPL 40x20x4x2[7/3.5] / N38
| Surface type | Friction coefficient / % Mocy | Max load (kg/lbs/g/N) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
2.26 kg / 4.97 LBS
2256.0 g / 22.1 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
1.50 kg / 3.32 LBS
1504.0 g / 14.8 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
0.75 kg / 1.66 LBS
752.0 g / 7.4 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
3.76 kg / 8.29 LBS
3760.0 g / 36.9 N
|
Table 4: Material efficiency (saturation) - power losses
MPL 40x20x4x2[7/3.5] / N38
| Steel thickness (mm) | % power | Real pull force (kg/lbs/g/N) |
|---|---|---|
| 0.5 mm |
|
0.75 kg / 1.66 LBS
752.0 g / 7.4 N
|
| 1 mm |
|
1.88 kg / 4.14 LBS
1880.0 g / 18.4 N
|
| 2 mm |
|
3.76 kg / 8.29 LBS
3760.0 g / 36.9 N
|
| 3 mm |
|
5.64 kg / 12.43 LBS
5640.0 g / 55.3 N
|
| 5 mm |
|
7.52 kg / 16.58 LBS
7520.0 g / 73.8 N
|
| 10 mm |
|
7.52 kg / 16.58 LBS
7520.0 g / 73.8 N
|
| 11 mm |
|
7.52 kg / 16.58 LBS
7520.0 g / 73.8 N
|
| 12 mm |
|
7.52 kg / 16.58 LBS
7520.0 g / 73.8 N
|
Table 5: Thermal resistance (material behavior) - power drop
MPL 40x20x4x2[7/3.5] / N38
| Ambient temp. (°C) | Power loss | Remaining pull (kg/lbs/g/N) | Status |
|---|---|---|---|
| 20 °C | 0.0% |
7.52 kg / 16.58 LBS
7520.0 g / 73.8 N
|
OK |
| 40 °C | -2.2% |
7.35 kg / 16.21 LBS
7354.6 g / 72.1 N
|
OK |
| 60 °C | -4.4% |
7.19 kg / 15.85 LBS
7189.1 g / 70.5 N
|
|
| 80 °C | -6.6% |
7.02 kg / 15.48 LBS
7023.7 g / 68.9 N
|
|
| 100 °C | -28.8% |
5.35 kg / 11.80 LBS
5354.2 g / 52.5 N
|
Table 6: Two magnets (repulsion) - field range
MPL 40x20x4x2[7/3.5] / N38
| Gap (mm) | Attraction (kg/lbs) (N-S) | Shear Strength (kg/lbs/g/N) | Repulsion (kg/lbs) (N-N) |
|---|---|---|---|
| 0 mm |
13.96 kg / 30.78 LBS
2 997 Gs
|
2.09 kg / 4.62 LBS
2094 g / 20.5 N
|
N/A |
| 1 mm |
13.44 kg / 29.64 LBS
3 302 Gs
|
2.02 kg / 4.45 LBS
2017 g / 19.8 N
|
12.10 kg / 26.68 LBS
~0 Gs
|
| 2 mm |
12.84 kg / 28.30 LBS
3 227 Gs
|
1.93 kg / 4.25 LBS
1926 g / 18.9 N
|
11.55 kg / 25.47 LBS
~0 Gs
|
| 3 mm |
12.17 kg / 26.83 LBS
3 142 Gs
|
1.83 kg / 4.02 LBS
1826 g / 17.9 N
|
10.95 kg / 24.15 LBS
~0 Gs
|
| 5 mm |
10.73 kg / 23.65 LBS
2 950 Gs
|
1.61 kg / 3.55 LBS
1609 g / 15.8 N
|
9.66 kg / 21.29 LBS
~0 Gs
|
| 10 mm |
7.19 kg / 15.84 LBS
2 414 Gs
|
1.08 kg / 2.38 LBS
1078 g / 10.6 N
|
6.47 kg / 14.26 LBS
~0 Gs
|
| 20 mm |
2.73 kg / 6.01 LBS
1 487 Gs
|
0.41 kg / 0.90 LBS
409 g / 4.0 N
|
2.46 kg / 5.41 LBS
~0 Gs
|
| 50 mm |
0.18 kg / 0.39 LBS
379 Gs
|
0.03 kg / 0.06 LBS
27 g / 0.3 N
|
0.16 kg / 0.35 LBS
~0 Gs
|
| 60 mm |
0.08 kg / 0.18 LBS
259 Gs
|
0.01 kg / 0.03 LBS
12 g / 0.1 N
|
0.07 kg / 0.16 LBS
~0 Gs
|
| 70 mm |
0.04 kg / 0.09 LBS
183 Gs
|
0.01 kg / 0.01 LBS
6 g / 0.1 N
|
0.04 kg / 0.08 LBS
~0 Gs
|
| 80 mm |
0.02 kg / 0.05 LBS
133 Gs
|
0.00 kg / 0.01 LBS
3 g / 0.0 N
|
0.02 kg / 0.04 LBS
~0 Gs
|
| 90 mm |
0.01 kg / 0.03 LBS
99 Gs
|
0.00 kg / 0.00 LBS
2 g / 0.0 N
|
0.01 kg / 0.02 LBS
~0 Gs
|
| 100 mm |
0.01 kg / 0.02 LBS
76 Gs
|
0.00 kg / 0.00 LBS
1 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
Table 7: Protective zones (implants) - precautionary measures
MPL 40x20x4x2[7/3.5] / N38
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 10.5 cm |
| Hearing aid | 10 Gs (1.0 mT) | 8.5 cm |
| Mechanical watch | 20 Gs (2.0 mT) | 6.5 cm |
| Phone / Smartphone | 40 Gs (4.0 mT) | 5.0 cm |
| Car key | 50 Gs (5.0 mT) | 4.5 cm |
| Payment card | 400 Gs (40.0 mT) | 2.0 cm |
| HDD hard drive | 600 Gs (60.0 mT) | 1.5 cm |
Table 8: Dynamics (kinetic energy) - warning
MPL 40x20x4x2[7/3.5] / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
19.91 km/h
(5.53 m/s)
|
0.37 J | |
| 30 mm |
31.03 km/h
(8.62 m/s)
|
0.89 J | |
| 50 mm |
39.93 km/h
(11.09 m/s)
|
1.48 J | |
| 100 mm |
56.45 km/h
(15.68 m/s)
|
2.95 J |
Table 9: Coating parameters (durability)
MPL 40x20x4x2[7/3.5] / 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 (Pc)
MPL 40x20x4x2[7/3.5] / N38
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 15 299 Mx | 153.0 µWb |
| Pc Coefficient | 0.19 | Low (Flat) |
Table 11: Physics of underwater searching
MPL 40x20x4x2[7/3.5] / N38
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 7.52 kg | Standard |
| Water (riverbed) |
8.61 kg
(+1.09 kg buoyancy gain)
|
+14.5% |
1. Sliding resistance
*Note: On a vertical surface, the magnet retains only a fraction of its perpendicular strength.
2. Steel thickness impact
*Thin steel (e.g. computer case) drastically reduces the holding force.
3. Power loss vs temp
*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) = 0.19
This simulation demonstrates the magnetic stability of the selected magnet under specific geometric conditions. 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.
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% |
Ecology and recycling (GPSR)
| recyclability (EoL) | 100% |
| recycled raw materials | ~10% (pre-cons) |
| carbon footprint | low / zredukowany |
| waste code (EWC) | 16 02 16 |
Other products
Advantages as well as disadvantages of Nd2Fe14B magnets.
Pros
- Their magnetic field is maintained, and after around 10 years it drops only by ~1% (according to research),
- They show high resistance to demagnetization induced by external magnetic fields,
- By using a lustrous coating of gold, the element acquires an professional look,
- Neodymium magnets create maximum magnetic induction on a small surface, which increases force concentration,
- Neodymium magnets are characterized by very high magnetic induction on the magnet surface and are able to act (depending on the form) even at a temperature of 230°C or more...
- Thanks to the option of precise shaping and adaptation to specialized projects, magnetic components can be produced in a wide range of geometric configurations, which expands the range of possible applications,
- Versatile presence in modern industrial fields – they are commonly used in HDD drives, electromotive mechanisms, diagnostic systems, as well as multitasking production systems.
- Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,
Limitations
- They are fragile upon too strong impacts. To avoid cracks, it is worth protecting magnets using a steel holder. Such protection not only shields the magnet but also improves its resistance to damage
- We warn that neodymium magnets can reduce their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 230°C.
- Magnets exposed to a humid environment can rust. Therefore when using outdoors, we suggest using water-impermeable magnets made of rubber, plastic or other material resistant to moisture
- We suggest cover - magnetic holder, due to difficulties in creating nuts inside the magnet and complicated forms.
- Potential hazard resulting from small fragments of magnets are risky, in case of ingestion, which becomes key in the context of child health protection. Furthermore, small components of these products can complicate diagnosis medical when they are in the body.
- High unit price – neodymium magnets have a higher price than other types of magnets (e.g. ferrite), which increases costs of application in large quantities
Pull force analysis
Maximum lifting capacity of the magnet – what it depends on?
- using a base made of low-carbon steel, serving as a circuit closing element
- possessing a thickness of min. 10 mm to ensure full flux closure
- characterized by lack of roughness
- without the slightest insulating layer between the magnet and steel
- for force applied at a right angle (in the magnet axis)
- at ambient temperature approx. 20 degrees Celsius
Determinants of practical lifting force of a magnet
- Distance – existence of any layer (rust, tape, air) interrupts the magnetic circuit, which lowers capacity rapidly (even by 50% at 0.5 mm).
- Force direction – catalog parameter refers to detachment vertically. When applying parallel force, the magnet exhibits significantly lower power (often approx. 20-30% of nominal force).
- Substrate thickness – to utilize 100% power, the steel must be adequately massive. Thin sheet restricts the attraction force (the magnet "punches through" it).
- Plate material – mild steel gives the best results. Alloy admixtures reduce magnetic permeability and holding force.
- Surface condition – smooth surfaces ensure maximum contact, which improves field saturation. Rough surfaces weaken the grip.
- Thermal factor – hot environment reduces pulling force. Too high temperature can permanently damage the magnet.
Lifting capacity was determined with the use of a smooth steel plate of suitable thickness (min. 20 mm), under vertically applied force, in contrast under attempts to slide the magnet the load capacity is reduced by as much as 75%. Moreover, even a slight gap between the magnet’s surface and the plate lowers the holding force.
Precautions when working with NdFeB magnets
Nickel coating and allergies
Certain individuals have a sensitization to Ni, which is the common plating for NdFeB magnets. Extended handling can result in a rash. It is best to wear protective gloves.
Heat warning
Keep cool. NdFeB magnets are sensitive to heat. If you require operation above 80°C, inquire about special high-temperature series (H, SH, UH).
Keep away from children
Only for adults. Tiny parts can be swallowed, leading to serious injuries. Store out of reach of kids and pets.
Pacemakers
Health Alert: Strong magnets can turn off heart devices and defibrillators. Do not approach if you have medical devices.
Risk of cracking
Despite metallic appearance, neodymium is brittle and not impact-resistant. Avoid impacts, as the magnet may shatter into hazardous fragments.
Handling guide
Before use, check safety instructions. Uncontrolled attraction can destroy the magnet or hurt your hand. Be predictive.
Serious injuries
Pinching hazard: The pulling power is so great that it can result in hematomas, crushing, and broken bones. Protective gloves are recommended.
Protect data
Do not bring magnets near a purse, laptop, or screen. The magnetic field can permanently damage these devices and wipe information from cards.
Phone sensors
Navigation devices and smartphones are highly sensitive to magnetic fields. Close proximity with a powerful NdFeB magnet can ruin the sensors in your phone.
Dust explosion hazard
Drilling and cutting of NdFeB material carries a risk of fire hazard. Neodymium dust reacts violently with oxygen and is difficult to extinguish.
