MP 14x8/4x3 / N38 - ring magnet
ring magnet
Catalog no 030181
GTIN/EAN: 5906301811985
Diameter
14 mm [±0,1 mm]
internal diameter Ø
8/4 mm [±0,1 mm]
Height
3 mm [±0,1 mm]
Weight
3.18 g
Magnetization Direction
↑ axial
Load capacity
2.53 kg / 24.85 N
Magnetic Induction
244.11 mT / 2441 Gs
Coating
[NiCuNi] Nickel
2.47 ZŁ with VAT / pcs + price for transport
2.01 ZŁ net + 23% VAT / pcs
bulk discounts:
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Technical data of the product - MP 14x8/4x3 / N38 - ring magnet
Specification / characteristics - MP 14x8/4x3 / N38 - ring magnet
| properties | values |
|---|---|
| Cat. no. | 030181 |
| GTIN/EAN | 5906301811985 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| Diameter | 14 mm [±0,1 mm] |
| internal diameter Ø | 8/4 mm [±0,1 mm] |
| Height | 3 mm [±0,1 mm] |
| Weight | 3.18 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 2.53 kg / 24.85 N |
| Magnetic Induction ~ ? | 244.11 mT / 2441 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 |
Physical analysis of the magnet - report
The following data are the outcome of a mathematical analysis. Results were calculated on models for the class Nd2Fe14B. Real-world performance might slightly differ from theoretical values. Please consider these data as a reference point for designers.
Table 1: Static force (pull vs gap) - interaction chart
MP 14x8/4x3 / N38
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg/lbs/g/N) | Risk Status |
|---|---|---|---|
| 0 mm |
2121 Gs
212.1 mT
|
2.53 kg / 5.58 LBS
2530.0 g / 24.8 N
|
medium risk |
| 1 mm |
1927 Gs
192.7 mT
|
2.09 kg / 4.61 LBS
2090.1 g / 20.5 N
|
medium risk |
| 2 mm |
1676 Gs
167.6 mT
|
1.58 kg / 3.48 LBS
1579.6 g / 15.5 N
|
weak grip |
| 3 mm |
1410 Gs
141.0 mT
|
1.12 kg / 2.46 LBS
1117.9 g / 11.0 N
|
weak grip |
| 5 mm |
943 Gs
94.3 mT
|
0.50 kg / 1.10 LBS
500.1 g / 4.9 N
|
weak grip |
| 10 mm |
335 Gs
33.5 mT
|
0.06 kg / 0.14 LBS
63.3 g / 0.6 N
|
weak grip |
| 15 mm |
140 Gs
14.0 mT
|
0.01 kg / 0.02 LBS
11.1 g / 0.1 N
|
weak grip |
| 20 mm |
69 Gs
6.9 mT
|
0.00 kg / 0.01 LBS
2.7 g / 0.0 N
|
weak grip |
| 30 mm |
24 Gs
2.4 mT
|
0.00 kg / 0.00 LBS
0.3 g / 0.0 N
|
weak grip |
| 50 mm |
6 Gs
0.6 mT
|
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
|
weak grip |
Table 2: Sliding force (wall)
MP 14x8/4x3 / N38
| Distance (mm) | Friction coefficient | Pull Force (kg/lbs/g/N) |
|---|---|---|
| 0 mm | Stal (~0.2) |
0.51 kg / 1.12 LBS
506.0 g / 5.0 N
|
| 1 mm | Stal (~0.2) |
0.42 kg / 0.92 LBS
418.0 g / 4.1 N
|
| 2 mm | Stal (~0.2) |
0.32 kg / 0.70 LBS
316.0 g / 3.1 N
|
| 3 mm | Stal (~0.2) |
0.22 kg / 0.49 LBS
224.0 g / 2.2 N
|
| 5 mm | Stal (~0.2) |
0.10 kg / 0.22 LBS
100.0 g / 1.0 N
|
| 10 mm | Stal (~0.2) |
0.01 kg / 0.03 LBS
12.0 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
MP 14x8/4x3 / N38
| Surface type | Friction coefficient / % Mocy | Max load (kg/lbs/g/N) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
0.76 kg / 1.67 LBS
759.0 g / 7.4 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
0.51 kg / 1.12 LBS
506.0 g / 5.0 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
0.25 kg / 0.56 LBS
253.0 g / 2.5 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
1.27 kg / 2.79 LBS
1265.0 g / 12.4 N
|
Table 4: Material efficiency (saturation) - power losses
MP 14x8/4x3 / N38
| Steel thickness (mm) | % power | Real pull force (kg/lbs/g/N) |
|---|---|---|
| 0.5 mm |
|
0.25 kg / 0.56 LBS
253.0 g / 2.5 N
|
| 1 mm |
|
0.63 kg / 1.39 LBS
632.5 g / 6.2 N
|
| 2 mm |
|
1.27 kg / 2.79 LBS
1265.0 g / 12.4 N
|
| 3 mm |
|
1.90 kg / 4.18 LBS
1897.5 g / 18.6 N
|
| 5 mm |
|
2.53 kg / 5.58 LBS
2530.0 g / 24.8 N
|
| 10 mm |
|
2.53 kg / 5.58 LBS
2530.0 g / 24.8 N
|
| 11 mm |
|
2.53 kg / 5.58 LBS
2530.0 g / 24.8 N
|
| 12 mm |
|
2.53 kg / 5.58 LBS
2530.0 g / 24.8 N
|
Table 5: Working in heat (stability) - thermal limit
MP 14x8/4x3 / N38
| Ambient temp. (°C) | Power loss | Remaining pull (kg/lbs/g/N) | Status |
|---|---|---|---|
| 20 °C | 0.0% |
2.53 kg / 5.58 LBS
2530.0 g / 24.8 N
|
OK |
| 40 °C | -2.2% |
2.47 kg / 5.45 LBS
2474.3 g / 24.3 N
|
OK |
| 60 °C | -4.4% |
2.42 kg / 5.33 LBS
2418.7 g / 23.7 N
|
|
| 80 °C | -6.6% |
2.36 kg / 5.21 LBS
2363.0 g / 23.2 N
|
|
| 100 °C | -28.8% |
1.80 kg / 3.97 LBS
1801.4 g / 17.7 N
|
Table 6: Two magnets (attraction) - field collision
MP 14x8/4x3 / N38
| Gap (mm) | Attraction (kg/lbs) (N-S) | Lateral Force (kg/lbs/g/N) | Repulsion (kg/lbs) (N-N) |
|---|---|---|---|
| 0 mm |
3.33 kg / 7.34 LBS
3 647 Gs
|
0.50 kg / 1.10 LBS
500 g / 4.9 N
|
N/A |
| 1 mm |
3.07 kg / 6.76 LBS
4 070 Gs
|
0.46 kg / 1.01 LBS
460 g / 4.5 N
|
2.76 kg / 6.09 LBS
~0 Gs
|
| 2 mm |
2.75 kg / 6.07 LBS
3 855 Gs
|
0.41 kg / 0.91 LBS
413 g / 4.0 N
|
2.48 kg / 5.46 LBS
~0 Gs
|
| 3 mm |
2.42 kg / 5.33 LBS
3 612 Gs
|
0.36 kg / 0.80 LBS
362 g / 3.6 N
|
2.17 kg / 4.79 LBS
~0 Gs
|
| 5 mm |
1.76 kg / 3.88 LBS
3 084 Gs
|
0.26 kg / 0.58 LBS
264 g / 2.6 N
|
1.59 kg / 3.50 LBS
~0 Gs
|
| 10 mm |
0.66 kg / 1.45 LBS
1 886 Gs
|
0.10 kg / 0.22 LBS
99 g / 1.0 N
|
0.59 kg / 1.31 LBS
~0 Gs
|
| 20 mm |
0.08 kg / 0.18 LBS
671 Gs
|
0.01 kg / 0.03 LBS
13 g / 0.1 N
|
0.08 kg / 0.17 LBS
~0 Gs
|
| 50 mm |
0.00 kg / 0.00 LBS
77 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
47 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
31 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
21 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
15 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
11 Gs
|
0.00 kg / 0.00 LBS
0 g / 0.0 N
|
0.00 kg / 0.00 LBS
~0 Gs
|
Table 7: Protective zones (implants) - warnings
MP 14x8/4x3 / N38
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 5.5 cm |
| Hearing aid | 10 Gs (1.0 mT) | 4.5 cm |
| Mechanical watch | 20 Gs (2.0 mT) | 3.5 cm |
| Phone / Smartphone | 40 Gs (4.0 mT) | 2.5 cm |
| Car key | 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: Collisions (kinetic energy) - collision effects
MP 14x8/4x3 / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
28.89 km/h
(8.02 m/s)
|
0.10 J | |
| 30 mm |
49.27 km/h
(13.69 m/s)
|
0.30 J | |
| 50 mm |
63.61 km/h
(17.67 m/s)
|
0.50 J | |
| 100 mm |
89.96 km/h
(24.99 m/s)
|
0.99 J |
Table 9: Anti-corrosion coating durability
MP 14x8/4x3 / 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 (Pc)
MP 14x8/4x3 / N38
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 3 101 Mx | 31.0 µWb |
| Pc Coefficient | 0.28 | Low (Flat) |
Table 11: Underwater work (magnet fishing)
MP 14x8/4x3 / N38
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 2.53 kg | Standard |
| Water (riverbed) |
2.90 kg
(+0.37 kg buoyancy gain)
|
+14.5% |
1. Sliding resistance
*Caution: On a vertical surface, the magnet retains only approx. 20-30% of its max power.
2. Efficiency vs thickness
*Thin metal sheet (e.g. 0.5mm PC case) drastically reduces the holding force.
3. Thermal stability
*For N38 material, the max working temp is 80°C.
4. Demagnetization curve and operating point (B-H)
chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.28
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.
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% |
Ecology and recycling (GPSR)
| recyclability (EoL) | 100% |
| recycled raw materials | ~10% (pre-cons) |
| carbon footprint | low / zredukowany |
| waste code (EWC) | 16 02 16 |
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Pros as well as cons of rare earth magnets.
Pros
- They virtually do not lose strength, because even after ten years the performance loss is only ~1% (according to literature),
- They possess excellent resistance to weakening of magnetic properties as a result of external magnetic sources,
- In other words, due to the metallic surface of gold, the element is aesthetically pleasing,
- Magnetic induction on the working layer of the magnet remains strong,
- Thanks to resistance to high temperature, they are capable of working (depending on the form) even at temperatures up to 230°C and higher...
- Due to the potential of flexible shaping and customization to specialized solutions, neodymium magnets can be produced in a broad palette of shapes and sizes, which amplifies use scope,
- Huge importance in advanced technology sectors – they are commonly used in HDD drives, electromotive mechanisms, diagnostic systems, as well as complex engineering applications.
- Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,
Disadvantages
- To avoid cracks upon strong impacts, we suggest using special steel holders. Such a solution secures the magnet and simultaneously increases its durability.
- 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 durability even at temperatures up to 230°C
- When exposed to humidity, magnets start to rust. For applications outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation as well as corrosion.
- Limited ability of making nuts in the magnet and complicated shapes - recommended is casing - magnetic holder.
- Health risk related to microscopic parts of magnets are risky, in case of ingestion, which becomes key in the context of child health protection. Additionally, small elements of these magnets are able to 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 can limit application in large quantities
Pull force analysis
Optimal lifting capacity of a neodymium magnet – what contributes to it?
- on a base made of structural steel, optimally conducting the magnetic field
- possessing a thickness of min. 10 mm to avoid saturation
- with a surface free of scratches
- without the slightest clearance between the magnet and steel
- for force acting at a right angle (pull-off, not shear)
- in temp. approx. 20°C
Determinants of lifting force in real conditions
- Space between magnet and steel – every millimeter of distance (caused e.g. by varnish or unevenness) significantly weakens the magnet efficiency, often by half at just 0.5 mm.
- Direction of force – maximum parameter is available only during perpendicular pulling. The resistance to sliding of the magnet along the surface is standardly several times lower (approx. 1/5 of the lifting capacity).
- Wall thickness – thin material does not allow full use of the magnet. Part of the magnetic field passes through the material instead of converting into lifting capacity.
- Plate material – low-carbon steel attracts best. Alloy admixtures reduce magnetic properties and holding force.
- Surface quality – the more even the surface, the better the adhesion and higher the lifting capacity. Unevenness creates an air distance.
- Operating temperature – neodymium magnets have a negative temperature coefficient. At higher temperatures they are weaker, and in frost they can be stronger (up to a certain limit).
Lifting capacity was determined using a steel plate with a smooth surface of suitable thickness (min. 20 mm), under vertically applied force, in contrast under shearing force the holding force is lower. Moreover, even a minimal clearance between the magnet’s surface and the plate reduces the lifting capacity.
Warnings
Product not for children
Product intended for adults. Small elements can be swallowed, leading to serious injuries. Store out of reach of children and animals.
ICD Warning
Patients with a heart stimulator must keep an absolute distance from magnets. The magnetic field can disrupt the functioning of the life-saving device.
Flammability
Drilling and cutting of NdFeB material carries a risk of fire hazard. Magnetic powder oxidizes rapidly with oxygen and is difficult to extinguish.
Finger safety
Danger of trauma: The pulling power is so great that it can result in hematomas, crushing, and broken bones. Use thick gloves.
Conscious usage
Before use, read the rules. Sudden snapping can break the magnet or hurt your hand. Think ahead.
Thermal limits
Do not overheat. NdFeB magnets are sensitive to heat. If you require operation above 80°C, look for HT versions (H, SH, UH).
Beware of splinters
Protect your eyes. Magnets can explode upon violent connection, ejecting shards into the air. Eye protection is mandatory.
Metal Allergy
Nickel alert: The Ni-Cu-Ni coating consists of nickel. If skin irritation appears, immediately stop working with magnets and use protective gear.
Threat to navigation
GPS units and smartphones are extremely susceptible to magnetism. Direct contact with a powerful NdFeB magnet can permanently damage the sensors in your phone.
Magnetic media
Equipment safety: Strong magnets can damage data carriers and delicate electronics (pacemakers, medical aids, mechanical watches).
