MP 25x5x27 / N38 - ring magnet
ring magnet
Catalog no 030192
GTIN/EAN: 5906301812098
- Diameter
- 25 mm [±0,1 mm]
- internal diameter Ø
- 5 mm [±0,1 mm]
- Height
- 27 mm [±0,1 mm]
- Weight
- 95.43 g
- Magnetization Direction
- ↑ axial
- Coating
- [NiCuNi] Nickel
47.18 zł with VAT / pcs + price for transport
38.36 zł net + 23% VAT / pcs
bulk discounts:
Need more?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.
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.
Order by 14:00 and we’ll ship today!
Technical of the product - MP 25x5x27 / N38 - ring magnet
Specification / characteristics - MP 25x5x27 / N38 - ring magnet
| properties | values |
|---|---|
| Cat. no. | 030192 |
| GTIN/EAN | 5906301812098 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| Diameter | 25 mm [±0,1 mm] |
| internal diameter Ø | 5 mm [±0,1 mm] |
| Height | 27 mm [±0,1 mm] |
| Weight | 95.43 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 18.51 kg / 181.54 N |
| Magnetic Induction ~ ? | 562.34 mT / 5623 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 |
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
MP 25x5x27 / N38
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg/lbs/g/N) | Risk Status |
|---|---|---|---|
| 0 mm |
5716 Gs
571.6 mT
|
18.51 kg / 40.81 LBS
18510.0 g / 181.6 N
|
critical level |
| 1 mm |
5288 Gs
528.8 mT
|
15.84 kg / 34.92 LBS
15839.8 g / 155.4 N
|
critical level |
| 2 mm |
4861 Gs
486.1 mT
|
13.38 kg / 29.51 LBS
13384.0 g / 131.3 N
|
critical level |
| 3 mm |
4446 Gs
444.6 mT
|
11.20 kg / 24.69 LBS
11198.0 g / 109.9 N
|
critical level |
| 5 mm |
3677 Gs
367.7 mT
|
7.66 kg / 16.88 LBS
7657.5 g / 75.1 N
|
strong |
| 10 mm |
2216 Gs
221.6 mT
|
2.78 kg / 6.13 LBS
2782.1 g / 27.3 N
|
strong |
| 15 mm |
1354 Gs
135.4 mT
|
1.04 kg / 2.29 LBS
1037.8 g / 10.2 N
|
weak grip |
| 20 mm |
864 Gs
86.4 mT
|
0.42 kg / 0.93 LBS
423.3 g / 4.2 N
|
weak grip |
| 30 mm |
405 Gs
40.5 mT
|
0.09 kg / 0.21 LBS
93.1 g / 0.9 N
|
weak grip |
| 50 mm |
133 Gs
13.3 mT
|
0.01 kg / 0.02 LBS
10.0 g / 0.1 N
|
weak grip |
Table 2: Sliding hold (vertical surface)
MP 25x5x27 / N38
| Distance (mm) | Friction coefficient | Pull Force (kg/lbs/g/N) |
|---|---|---|
| 0 mm | Stal (~0.2) |
3.70 kg / 8.16 LBS
3702.0 g / 36.3 N
|
| 1 mm | Stal (~0.2) |
3.17 kg / 6.98 LBS
3168.0 g / 31.1 N
|
| 2 mm | Stal (~0.2) |
2.68 kg / 5.90 LBS
2676.0 g / 26.3 N
|
| 3 mm | Stal (~0.2) |
2.24 kg / 4.94 LBS
2240.0 g / 22.0 N
|
| 5 mm | Stal (~0.2) |
1.53 kg / 3.38 LBS
1532.0 g / 15.0 N
|
| 10 mm | Stal (~0.2) |
0.56 kg / 1.23 LBS
556.0 g / 5.5 N
|
| 15 mm | Stal (~0.2) |
0.21 kg / 0.46 LBS
208.0 g / 2.0 N
|
| 20 mm | Stal (~0.2) |
0.08 kg / 0.19 LBS
84.0 g / 0.8 N
|
| 30 mm | Stal (~0.2) |
0.02 kg / 0.04 LBS
18.0 g / 0.2 N
|
| 50 mm | Stal (~0.2) |
0.00 kg / 0.00 LBS
2.0 g / 0.0 N
|
Table 3: Vertical assembly (shearing) - vertical pull
MP 25x5x27 / N38
| Surface type | Friction coefficient / % Mocy | Max load (kg/lbs/g/N) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
5.55 kg / 12.24 LBS
5553.0 g / 54.5 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
3.70 kg / 8.16 LBS
3702.0 g / 36.3 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
1.85 kg / 4.08 LBS
1851.0 g / 18.2 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
9.26 kg / 20.40 LBS
9255.0 g / 90.8 N
|
Table 4: Material efficiency (saturation) - sheet metal selection
MP 25x5x27 / N38
| Steel thickness (mm) | % power | Real pull force (kg/lbs/g/N) |
|---|---|---|
| 0.5 mm |
|
0.93 kg / 2.04 LBS
925.5 g / 9.1 N
|
| 1 mm |
|
2.31 kg / 5.10 LBS
2313.8 g / 22.7 N
|
| 2 mm |
|
4.63 kg / 10.20 LBS
4627.5 g / 45.4 N
|
| 3 mm |
|
6.94 kg / 15.30 LBS
6941.3 g / 68.1 N
|
| 5 mm |
|
11.57 kg / 25.50 LBS
11568.8 g / 113.5 N
|
| 10 mm |
|
18.51 kg / 40.81 LBS
18510.0 g / 181.6 N
|
| 11 mm |
|
18.51 kg / 40.81 LBS
18510.0 g / 181.6 N
|
| 12 mm |
|
18.51 kg / 40.81 LBS
18510.0 g / 181.6 N
|
Table 5: Thermal stability (stability) - power drop
MP 25x5x27 / N38
| Ambient temp. (°C) | Power loss | Remaining pull (kg/lbs/g/N) | Status |
|---|---|---|---|
| 20 °C | 0.0% |
18.51 kg / 40.81 LBS
18510.0 g / 181.6 N
|
OK |
| 40 °C | -2.2% |
18.10 kg / 39.91 LBS
18102.8 g / 177.6 N
|
OK |
| 60 °C | -4.4% |
17.70 kg / 39.01 LBS
17695.6 g / 173.6 N
|
OK |
| 80 °C | -6.6% |
17.29 kg / 38.11 LBS
17288.3 g / 169.6 N
|
|
| 100 °C | -28.8% |
13.18 kg / 29.05 LBS
13179.1 g / 129.3 N
|
Table 6: Two magnets (repulsion) - field collision
MP 25x5x27 / N38
| Gap (mm) | Attraction (kg/lbs) (N-S) | Lateral Force (kg/lbs/g/N) | Repulsion (kg/lbs) (N-N) |
|---|---|---|---|
| 0 mm |
13.99 kg / 30.83 LBS
6 064 Gs
|
2.10 kg / 4.62 LBS
2098 g / 20.6 N
|
N/A |
| 1 mm |
12.97 kg / 28.59 LBS
11 008 Gs
|
1.94 kg / 4.29 LBS
1945 g / 19.1 N
|
11.67 kg / 25.73 LBS
~0 Gs
|
| 2 mm |
11.97 kg / 26.39 LBS
10 576 Gs
|
1.80 kg / 3.96 LBS
1795 g / 17.6 N
|
10.77 kg / 23.75 LBS
~0 Gs
|
| 3 mm |
11.02 kg / 24.29 LBS
10 146 Gs
|
1.65 kg / 3.64 LBS
1652 g / 16.2 N
|
9.91 kg / 21.86 LBS
~0 Gs
|
| 5 mm |
9.26 kg / 20.42 LBS
9 303 Gs
|
1.39 kg / 3.06 LBS
1389 g / 13.6 N
|
8.33 kg / 18.37 LBS
~0 Gs
|
| 10 mm |
5.79 kg / 12.76 LBS
7 353 Gs
|
0.87 kg / 1.91 LBS
868 g / 8.5 N
|
5.21 kg / 11.48 LBS
~0 Gs
|
| 20 mm |
2.10 kg / 4.63 LBS
4 432 Gs
|
0.32 kg / 0.70 LBS
315 g / 3.1 N
|
1.89 kg / 4.17 LBS
~0 Gs
|
| 50 mm |
0.14 kg / 0.32 LBS
1 159 Gs
|
0.02 kg / 0.05 LBS
22 g / 0.2 N
|
0.13 kg / 0.29 LBS
~0 Gs
|
| 60 mm |
0.07 kg / 0.16 LBS
811 Gs
|
0.01 kg / 0.02 LBS
11 g / 0.1 N
|
0.06 kg / 0.14 LBS
~0 Gs
|
| 70 mm |
0.04 kg / 0.08 LBS
589 Gs
|
0.01 kg / 0.01 LBS
6 g / 0.1 N
|
0.03 kg / 0.07 LBS
~0 Gs
|
| 80 mm |
0.02 kg / 0.05 LBS
440 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
338 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
265 Gs
|
0.00 kg / 0.00 LBS
1 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
Table 7: Hazards (implants) - warnings
MP 25x5x27 / N38
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 18.0 cm |
| Hearing aid | 10 Gs (1.0 mT) | 14.0 cm |
| Mechanical watch | 20 Gs (2.0 mT) | 11.0 cm |
| Mobile device | 40 Gs (4.0 mT) | 8.5 cm |
| Remote | 50 Gs (5.0 mT) | 7.5 cm |
| Payment card | 400 Gs (40.0 mT) | 3.5 cm |
| HDD hard drive | 600 Gs (60.0 mT) | 2.5 cm |
Table 8: Impact energy (kinetic energy) - warning
MP 25x5x27 / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
15.21 km/h
(4.23 m/s)
|
0.85 J | |
| 30 mm |
16.42 km/h
(4.56 m/s)
|
0.99 J | |
| 50 mm |
16.47 km/h
(4.58 m/s)
|
1.00 J | |
| 100 mm |
16.48 km/h
(4.58 m/s)
|
1.00 J |
Table 9: Anti-corrosion coating durability
MP 25x5x27 / 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)
MP 25x5x27 / N38
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 4 917 Mx | 49.2 µWb |
| Pc Coefficient | 1.40 | High (Stable) |
Table 11: Physics of underwater searching
MP 25x5x27 / N38
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 18.51 kg | Standard |
| Water (riverbed) |
21.19 kg
(+2.68 kg buoyancy gain)
|
+14.5% |
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) = 1.40
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.
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 |
Other offers
Advantages as well as disadvantages of Nd2Fe14B magnets.
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
- 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 magnet – what contributes to it?
- 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
- 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
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.
Health Danger
Life threat: Neodymium magnets can turn off pacemakers and defibrillators. Stay away if you have medical devices.
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.
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!
Handling guide
Handle magnets consciously. Their immense force can surprise even professionals. Stay alert and do not underestimate their power.
Safe distance
Intense magnetic fields can corrupt files on credit cards, hard drives, and storage devices. Stay away of at least 10 cm.
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).
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.
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.
