MP 40x10.4/5.5x5 / N38 - ring magnet
ring magnet
Catalog no 030249
GTIN/EAN: 5906301812258
Diameter
40 mm [±0,1 mm]
internal diameter Ø
10.4/5.5 mm [±0,1 mm]
Height
5 mm [±0,1 mm]
Weight
46.23 g
Magnetization Direction
↑ axial
Load capacity
9.47 kg / 92.86 N
Magnetic Induction
150.36 mT / 1504 Gs
Coating
[NiCuNi] Nickel
27.00 ZŁ with VAT / pcs + price for transport
21.95 ZŁ net + 23% VAT / pcs
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Product card - MP 40x10.4/5.5x5 / N38 - ring magnet
Specification / characteristics - MP 40x10.4/5.5x5 / N38 - ring magnet
| properties | values |
|---|---|
| Cat. no. | 030249 |
| GTIN/EAN | 5906301812258 |
| Production/Distribution | Dhit sp. z o.o. |
| Country of origin | Poland / China / Germany |
| Customs code | 85059029 |
| Diameter | 40 mm [±0,1 mm] |
| internal diameter Ø | 10.4/5.5 mm [±0,1 mm] |
| Height | 5 mm [±0,1 mm] |
| Weight | 46.23 g |
| Magnetization Direction | ↑ axial |
| Load capacity ~ ? | 9.47 kg / 92.86 N |
| Magnetic Induction ~ ? | 150.36 mT / 1504 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 - report
These information constitute the direct effect of a mathematical simulation. Values were calculated on algorithms for the material Nd2Fe14B. Actual parameters might slightly differ. Please consider these calculations as a supplementary guide during assembly planning.
Table 1: Static pull force (force vs distance) - characteristics
MP 40x10.4/5.5x5 / N38
| Distance (mm) | Induction (Gauss) / mT | Pull Force (kg) | Risk Status |
|---|---|---|---|
| 0 mm |
1289 Gs
128.9 mT
|
9.47 kg / 9470.0 g
92.9 N
|
medium risk |
| 1 mm |
1265 Gs
126.5 mT
|
9.12 kg / 9120.9 g
89.5 N
|
medium risk |
| 2 mm |
1232 Gs
123.2 mT
|
8.66 kg / 8662.7 g
85.0 N
|
medium risk |
| 3 mm |
1193 Gs
119.3 mT
|
8.12 kg / 8121.3 g
79.7 N
|
medium risk |
| 5 mm |
1099 Gs
109.9 mT
|
6.89 kg / 6887.8 g
67.6 N
|
medium risk |
| 10 mm |
825 Gs
82.5 mT
|
3.88 kg / 3882.0 g
38.1 N
|
medium risk |
| 15 mm |
580 Gs
58.0 mT
|
1.92 kg / 1915.5 g
18.8 N
|
safe |
| 20 mm |
399 Gs
39.9 mT
|
0.91 kg / 908.3 g
8.9 N
|
safe |
| 30 mm |
195 Gs
19.5 mT
|
0.22 kg / 217.6 g
2.1 N
|
safe |
| 50 mm |
61 Gs
6.1 mT
|
0.02 kg / 21.0 g
0.2 N
|
safe |
Table 2: Sliding hold (vertical surface)
MP 40x10.4/5.5x5 / N38
| Distance (mm) | Friction coefficient | Pull Force (kg) |
|---|---|---|
| 0 mm | Stal (~0.2) |
1.89 kg / 1894.0 g
18.6 N
|
| 1 mm | Stal (~0.2) |
1.82 kg / 1824.0 g
17.9 N
|
| 2 mm | Stal (~0.2) |
1.73 kg / 1732.0 g
17.0 N
|
| 3 mm | Stal (~0.2) |
1.62 kg / 1624.0 g
15.9 N
|
| 5 mm | Stal (~0.2) |
1.38 kg / 1378.0 g
13.5 N
|
| 10 mm | Stal (~0.2) |
0.78 kg / 776.0 g
7.6 N
|
| 15 mm | Stal (~0.2) |
0.38 kg / 384.0 g
3.8 N
|
| 20 mm | Stal (~0.2) |
0.18 kg / 182.0 g
1.8 N
|
| 30 mm | Stal (~0.2) |
0.04 kg / 44.0 g
0.4 N
|
| 50 mm | Stal (~0.2) |
0.00 kg / 4.0 g
0.0 N
|
Table 3: Vertical assembly (sliding) - behavior on slippery surfaces
MP 40x10.4/5.5x5 / N38
| Surface type | Friction coefficient / % Mocy | Max load (kg) |
|---|---|---|
| Raw steel |
µ = 0.3
30% Nominalnej Siły
|
2.84 kg / 2841.0 g
27.9 N
|
| Painted steel (standard) |
µ = 0.2
20% Nominalnej Siły
|
1.89 kg / 1894.0 g
18.6 N
|
| Oily/slippery steel |
µ = 0.1
10% Nominalnej Siły
|
0.95 kg / 947.0 g
9.3 N
|
| Magnet with anti-slip rubber |
µ = 0.5
50% Nominalnej Siły
|
4.74 kg / 4735.0 g
46.5 N
|
Table 4: Steel thickness (saturation) - power losses
MP 40x10.4/5.5x5 / N38
| Steel thickness (mm) | % power | Real pull force (kg) |
|---|---|---|
| 0.5 mm |
|
0.95 kg / 947.0 g
9.3 N
|
| 1 mm |
|
2.37 kg / 2367.5 g
23.2 N
|
| 2 mm |
|
4.74 kg / 4735.0 g
46.5 N
|
| 5 mm |
|
9.47 kg / 9470.0 g
92.9 N
|
| 10 mm |
|
9.47 kg / 9470.0 g
92.9 N
|
Table 5: Thermal stability (stability) - resistance threshold
MP 40x10.4/5.5x5 / N38
| Ambient temp. (°C) | Power loss | Remaining pull | Status |
|---|---|---|---|
| 20 °C | 0.0% |
9.47 kg / 9470.0 g
92.9 N
|
OK |
| 40 °C | -2.2% |
9.26 kg / 9261.7 g
90.9 N
|
OK |
| 60 °C | -4.4% |
9.05 kg / 9053.3 g
88.8 N
|
|
| 80 °C | -6.6% |
8.84 kg / 8845.0 g
86.8 N
|
|
| 100 °C | -28.8% |
6.74 kg / 6742.6 g
66.1 N
|
Table 6: Two magnets (attraction) - forces in the system
MP 40x10.4/5.5x5 / N38
| Gap (mm) | Attraction (kg) (N-S) | Repulsion (kg) (N-N) |
|---|---|---|
| 0 mm |
10.73 kg / 10727 g
105.2 N
2 424 Gs
|
N/A |
| 1 mm |
10.55 kg / 10547 g
103.5 N
2 555 Gs
|
9.49 kg / 9492 g
93.1 N
~0 Gs
|
| 2 mm |
10.33 kg / 10331 g
101.3 N
2 529 Gs
|
9.30 kg / 9298 g
91.2 N
~0 Gs
|
| 3 mm |
10.09 kg / 10085 g
98.9 N
2 499 Gs
|
9.08 kg / 9077 g
89.0 N
~0 Gs
|
| 5 mm |
9.52 kg / 9516 g
93.3 N
2 427 Gs
|
8.56 kg / 8564 g
84.0 N
~0 Gs
|
| 10 mm |
7.80 kg / 7802 g
76.5 N
2 198 Gs
|
7.02 kg / 7022 g
68.9 N
~0 Gs
|
| 20 mm |
4.40 kg / 4397 g
43.1 N
1 650 Gs
|
3.96 kg / 3957 g
38.8 N
~0 Gs
|
| 50 mm |
0.49 kg / 494 g
4.8 N
553 Gs
|
0.44 kg / 445 g
4.4 N
~0 Gs
|
Table 7: Protective zones (electronics) - precautionary measures
MP 40x10.4/5.5x5 / N38
| Object / Device | Limit (Gauss) / mT | Safe distance |
|---|---|---|
| Pacemaker | 5 Gs (0.5 mT) | 12.5 cm |
| Hearing aid | 10 Gs (1.0 mT) | 10.0 cm |
| Timepiece | 20 Gs (2.0 mT) | 8.0 cm |
| Phone / Smartphone | 40 Gs (4.0 mT) | 6.0 cm |
| Car key | 50 Gs (5.0 mT) | 5.5 cm |
| Payment card | 400 Gs (40.0 mT) | 2.0 cm |
| HDD hard drive | 600 Gs (60.0 mT) | 1.5 cm |
Table 8: Impact energy (cracking risk) - warning
MP 40x10.4/5.5x5 / N38
| Start from (mm) | Speed (km/h) | Energy (J) | Predicted outcome |
|---|---|---|---|
| 10 mm |
17.75 km/h
(4.93 m/s)
|
0.56 J | |
| 30 mm |
25.36 km/h
(7.04 m/s)
|
1.15 J | |
| 50 mm |
32.32 km/h
(8.98 m/s)
|
1.86 J | |
| 100 mm |
45.65 km/h
(12.68 m/s)
|
3.72 J |
Table 9: Coating parameters (durability)
MP 40x10.4/5.5x5 / 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 40x10.4/5.5x5 / N38
| Parameter | Value | SI Unit / Description |
|---|---|---|
| Magnetic Flux | 17 767 Mx | 177.7 µWb |
| Pc Coefficient | 0.17 | Low (Flat) |
Table 11: Hydrostatics and buoyancy
MP 40x10.4/5.5x5 / N38
| Environment | Effective steel pull | Effect |
|---|---|---|
| Air (land) | 9.47 kg | Standard |
| Water (riverbed) |
10.84 kg
(+1.37 kg Buoyancy gain)
|
+14.5% |
1. Sliding resistance
*Caution: On a vertical surface, the magnet retains just approx. 20-30% of its nominal pull.
2. Plate thickness effect
*Thin steel (e.g. 0.5mm PC case) drastically limits the holding force.
3. Heat tolerance
*For standard magnets, the max working temp is 80°C.
4. Demagnetization curve and operating point (B-H)
chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.17
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% |
Environmental data
| recyclability (EoL) | 100% |
| recycled raw materials | ~10% (pre-cons) |
| carbon footprint | low / zredukowany |
| waste code (EWC) | 16 02 16 |
Check out also offers
Advantages as well as disadvantages of neodymium magnets.
Pros
- Their strength is durable, and after approximately ten years it drops only by ~1% (theoretically),
- They are resistant to demagnetization induced by external magnetic fields,
- By using a reflective coating of silver, the element acquires an proper look,
- Magnetic induction on the surface of the magnet turns out to be very high,
- Through (adequate) combination of ingredients, they can achieve high thermal resistance, allowing for operation at temperatures reaching 230°C and above...
- Thanks to freedom in forming and the ability to adapt to complex applications,
- Universal use in high-tech industry – they serve a role in computer drives, electric drive systems, medical equipment, as well as modern systems.
- Thanks to concentrated force, small magnets offer high operating force, with minimal size,
Cons
- At very strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
- NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent drop of power (a factor is the shape and dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are extremely resistant to heat
- Magnets exposed to a humid environment can corrode. Therefore during using outdoors, we suggest using waterproof magnets made of rubber, plastic or other material resistant to moisture
- Limited ability of making threads in the magnet and complicated shapes - preferred is casing - magnet mounting.
- Possible danger resulting from small fragments of magnets are risky, when accidentally swallowed, which gains importance in the context of child health protection. Additionally, small elements of these devices are able to disrupt the diagnostic process medical in case of swallowing.
- Due to expensive raw materials, their price is higher than average,
Lifting parameters
Maximum lifting capacity of the magnet – what it depends on?
- on a block made of mild steel, effectively closing the magnetic flux
- whose transverse dimension reaches at least 10 mm
- characterized by smoothness
- under conditions of no distance (metal-to-metal)
- under perpendicular application of breakaway force (90-degree angle)
- at standard ambient temperature
Determinants of lifting force in real conditions
- Distance – the presence of foreign body (paint, dirt, air) interrupts the magnetic circuit, which reduces power rapidly (even by 50% at 0.5 mm).
- Force direction – catalog parameter refers to pulling vertically. When slipping, the magnet holds significantly lower power (often approx. 20-30% of maximum force).
- Metal 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.
- Material composition – not every steel reacts the same. Alloy additives worsen the interaction with the magnet.
- Surface finish – full contact is possible only on smooth steel. Rough texture reduce the real contact area, reducing force.
- Thermal conditions – NdFeB sinters have a sensitivity to temperature. When it is hot they lose power, and at low temperatures they can be stronger (up to a certain limit).
Holding force was checked on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, whereas under shearing force the holding force is lower. Moreover, even a small distance between the magnet and the plate decreases the lifting capacity.
Safety rules for work with neodymium magnets
Finger safety
Mind your fingers. Two large magnets will snap together instantly with a force of several hundred kilograms, destroying everything in their path. Exercise extreme caution!
Do not give to children
Product intended for adults. Small elements can be swallowed, causing intestinal necrosis. Store away from kids and pets.
Nickel coating and allergies
Warning for allergy sufferers: The nickel-copper-nickel coating consists of nickel. If an allergic reaction appears, immediately stop handling magnets and wear gloves.
Conscious usage
Be careful. Rare earth magnets attract from a distance and connect with huge force, often quicker than you can react.
Keep away from computers
Equipment safety: Neodymium magnets can damage payment cards and sensitive devices (heart implants, medical aids, mechanical watches).
Mechanical processing
Dust generated during cutting of magnets is self-igniting. Avoid drilling into magnets without proper cooling and knowledge.
Permanent damage
Watch the temperature. Exposing the magnet above 80 degrees Celsius will ruin its properties and pulling force.
Material brittleness
Despite metallic appearance, neodymium is delicate and cannot withstand shocks. Avoid impacts, as the magnet may crumble into sharp, dangerous pieces.
Implant safety
Life threat: Neodymium magnets can deactivate pacemakers and defibrillators. Stay away if you have electronic implants.
GPS and phone interference
Navigation devices and smartphones are highly sensitive to magnetic fields. Close proximity with a powerful NdFeB magnet can ruin the sensors in your phone.
