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MP 30x6x10 / N38 - ring magnet

ring magnet

Catalog no 030197

GTIN/EAN: 5906301812142

5.00

Diameter

30 mm [±0,1 mm]

internal diameter Ø

6 mm [±0,1 mm]

Height

10 mm [±0,1 mm]

Weight

50.89 g

Magnetization Direction

↑ axial

Load capacity

20.71 kg / 203.16 N

Magnetic Induction

343.81 mT / 3438 Gs

Coating

[NiCuNi] Nickel

16.00 with VAT / pcs + price for transport

13.01 ZŁ net + 23% VAT / pcs

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Strength as well as shape of neodymium magnets can be analyzed with our modular calculator.

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Physical properties - MP 30x6x10 / N38 - ring magnet

Specification / characteristics - MP 30x6x10 / N38 - ring magnet

properties
properties values
Cat. no. 030197
GTIN/EAN 5906301812142
Production/Distribution Dhit sp. z o.o.
ul. Zielona 14 05-850 Ożarów Mazowiecki PL
Country of origin Poland / China / Germany
Customs code 85059029
Diameter 30 mm [±0,1 mm]
internal diameter Ø 6 mm [±0,1 mm]
Height 10 mm [±0,1 mm]
Weight 50.89 g
Magnetization Direction ↑ axial
Load capacity ~ ? 20.71 kg / 203.16 N
Magnetic Induction ~ ? 343.81 mT / 3438 Gs
Coating [NiCuNi] Nickel
Manufacturing Tolerance ±0.1 mm

Magnetic properties of material N38

Specification / characteristics MP 30x6x10 / N38 - ring magnet
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

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 assembly - technical parameters

The following information are the result of a mathematical simulation. Results were calculated on models for the class Nd2Fe14B. Real-world parameters might slightly deviate from the simulation results. Treat these calculations as a reference point for designers.

Table 1: Static force (pull vs distance) - interaction chart
MP 30x6x10 / N38

Distance (mm) Induction (Gauss) / mT Pull Force (kg/lbs/g/N) Risk Status
0 mm 5619 Gs
561.9 mT
20.71 kg / 45.66 LBS
20710.0 g / 203.2 N
critical level
1 mm 5241 Gs
524.1 mT
18.01 kg / 39.71 LBS
18011.7 g / 176.7 N
critical level
2 mm 4861 Gs
486.1 mT
15.50 kg / 34.17 LBS
15498.1 g / 152.0 N
critical level
3 mm 4490 Gs
449.0 mT
13.22 kg / 29.15 LBS
13223.5 g / 129.7 N
critical level
5 mm 3792 Gs
379.2 mT
9.43 kg / 20.79 LBS
9429.0 g / 92.5 N
medium risk
10 mm 2404 Gs
240.4 mT
3.79 kg / 8.36 LBS
3791.3 g / 37.2 N
medium risk
15 mm 1526 Gs
152.6 mT
1.53 kg / 3.37 LBS
1527.0 g / 15.0 N
low risk
20 mm 1000 Gs
100.0 mT
0.66 kg / 1.45 LBS
655.5 g / 6.4 N
low risk
30 mm 482 Gs
48.2 mT
0.15 kg / 0.34 LBS
152.6 g / 1.5 N
low risk
50 mm 161 Gs
16.1 mT
0.02 kg / 0.04 LBS
17.0 g / 0.2 N
low risk

Table 2: Sliding force (vertical surface)
MP 30x6x10 / N38

Distance (mm) Friction coefficient Pull Force (kg/lbs/g/N)
0 mm Stal (~0.2) 4.14 kg / 9.13 LBS
4142.0 g / 40.6 N
1 mm Stal (~0.2) 3.60 kg / 7.94 LBS
3602.0 g / 35.3 N
2 mm Stal (~0.2) 3.10 kg / 6.83 LBS
3100.0 g / 30.4 N
3 mm Stal (~0.2) 2.64 kg / 5.83 LBS
2644.0 g / 25.9 N
5 mm Stal (~0.2) 1.89 kg / 4.16 LBS
1886.0 g / 18.5 N
10 mm Stal (~0.2) 0.76 kg / 1.67 LBS
758.0 g / 7.4 N
15 mm Stal (~0.2) 0.31 kg / 0.67 LBS
306.0 g / 3.0 N
20 mm Stal (~0.2) 0.13 kg / 0.29 LBS
132.0 g / 1.3 N
30 mm Stal (~0.2) 0.03 kg / 0.07 LBS
30.0 g / 0.3 N
50 mm Stal (~0.2) 0.00 kg / 0.01 LBS
4.0 g / 0.0 N

Table 3: Wall mounting (sliding) - vertical pull
MP 30x6x10 / N38

Surface type Friction coefficient / % Mocy Max load (kg/lbs/g/N)
Raw steel
µ = 0.3 30% Nominalnej Siły
6.21 kg / 13.70 LBS
6213.0 g / 60.9 N
Painted steel (standard)
µ = 0.2 20% Nominalnej Siły
4.14 kg / 9.13 LBS
4142.0 g / 40.6 N
Oily/slippery steel
µ = 0.1 10% Nominalnej Siły
2.07 kg / 4.57 LBS
2071.0 g / 20.3 N
Magnet with anti-slip rubber
µ = 0.5 50% Nominalnej Siły
10.36 kg / 22.83 LBS
10355.0 g / 101.6 N

Table 4: Steel thickness (substrate influence) - power losses
MP 30x6x10 / N38

Steel thickness (mm) % power Real pull force (kg/lbs/g/N)
0.5 mm
5%
1.04 kg / 2.28 LBS
1035.5 g / 10.2 N
1 mm
13%
2.59 kg / 5.71 LBS
2588.8 g / 25.4 N
2 mm
25%
5.18 kg / 11.41 LBS
5177.5 g / 50.8 N
3 mm
38%
7.77 kg / 17.12 LBS
7766.3 g / 76.2 N
5 mm
63%
12.94 kg / 28.54 LBS
12943.8 g / 127.0 N
10 mm
100%
20.71 kg / 45.66 LBS
20710.0 g / 203.2 N
11 mm
100%
20.71 kg / 45.66 LBS
20710.0 g / 203.2 N
12 mm
100%
20.71 kg / 45.66 LBS
20710.0 g / 203.2 N

Table 5: Working in heat (stability) - thermal limit
MP 30x6x10 / N38

Ambient temp. (°C) Power loss Remaining pull (kg/lbs/g/N) Status
20 °C 0.0% 20.71 kg / 45.66 LBS
20710.0 g / 203.2 N
OK
40 °C -2.2% 20.25 kg / 44.65 LBS
20254.4 g / 198.7 N
OK
60 °C -4.4% 19.80 kg / 43.65 LBS
19798.8 g / 194.2 N
OK
80 °C -6.6% 19.34 kg / 42.64 LBS
19343.1 g / 189.8 N
100 °C -28.8% 14.75 kg / 32.51 LBS
14745.5 g / 144.7 N

Table 6: Two magnets (repulsion) - forces in the system
MP 30x6x10 / N38

Gap (mm) Attraction (kg/lbs) (N-S) Sliding Force (kg/lbs/g/N) Repulsion (kg/lbs) (N-N)
0 mm 103.97 kg / 229.22 LBS
6 035 Gs
15.60 kg / 34.38 LBS
15596 g / 153.0 N
N/A
1 mm 97.15 kg / 214.17 LBS
10 864 Gs
14.57 kg / 32.13 LBS
14572 g / 143.0 N
87.43 kg / 192.75 LBS
~0 Gs
2 mm 90.42 kg / 199.35 LBS
10 481 Gs
13.56 kg / 29.90 LBS
13564 g / 133.1 N
81.38 kg / 179.42 LBS
~0 Gs
3 mm 83.97 kg / 185.13 LBS
10 100 Gs
12.60 kg / 27.77 LBS
12596 g / 123.6 N
75.57 kg / 166.61 LBS
~0 Gs
5 mm 71.94 kg / 158.60 LBS
9 349 Gs
10.79 kg / 23.79 LBS
10791 g / 105.9 N
64.75 kg / 142.74 LBS
~0 Gs
10 mm 47.34 kg / 104.36 LBS
7 583 Gs
7.10 kg / 15.65 LBS
7100 g / 69.7 N
42.60 kg / 93.92 LBS
~0 Gs
20 mm 19.03 kg / 41.96 LBS
4 809 Gs
2.86 kg / 6.29 LBS
2855 g / 28.0 N
17.13 kg / 37.77 LBS
~0 Gs
50 mm 1.53 kg / 3.37 LBS
1 363 Gs
0.23 kg / 0.51 LBS
229 g / 2.2 N
1.38 kg / 3.03 LBS
~0 Gs
60 mm 0.77 kg / 1.69 LBS
965 Gs
0.11 kg / 0.25 LBS
115 g / 1.1 N
0.69 kg / 1.52 LBS
~0 Gs
70 mm 0.41 kg / 0.90 LBS
706 Gs
0.06 kg / 0.14 LBS
61 g / 0.6 N
0.37 kg / 0.81 LBS
~0 Gs
80 mm 0.23 kg / 0.51 LBS
531 Gs
0.03 kg / 0.08 LBS
35 g / 0.3 N
0.21 kg / 0.46 LBS
~0 Gs
90 mm 0.14 kg / 0.30 LBS
409 Gs
0.02 kg / 0.05 LBS
21 g / 0.2 N
0.12 kg / 0.27 LBS
~0 Gs
100 mm 0.09 kg / 0.19 LBS
322 Gs
0.01 kg / 0.03 LBS
13 g / 0.1 N
0.08 kg / 0.17 LBS
~0 Gs

Table 7: Hazards (implants) - warnings
MP 30x6x10 / N38

Object / Device Limit (Gauss) / mT Safe distance
Pacemaker 5 Gs (0.5 mT) 19.5 cm
Hearing aid 10 Gs (1.0 mT) 15.0 cm
Mechanical watch 20 Gs (2.0 mT) 12.0 cm
Phone / Smartphone 40 Gs (4.0 mT) 9.0 cm
Car key 50 Gs (5.0 mT) 8.5 cm
Payment card 400 Gs (40.0 mT) 3.5 cm
HDD hard drive 600 Gs (60.0 mT) 3.0 cm

Table 8: Collisions (kinetic energy) - warning
MP 30x6x10 / N38

Start from (mm) Speed (km/h) Energy (J) Predicted outcome
10 mm 22.55 km/h
(6.26 m/s)
1.00 J
30 mm 35.40 km/h
(9.83 m/s)
2.46 J
50 mm 45.52 km/h
(12.64 m/s)
4.07 J
100 mm 64.34 km/h
(17.87 m/s)
8.13 J

Table 9: Surface protection spec
MP 30x6x10 / 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 30x6x10 / N38

Parameter Value SI Unit / Description
Magnetic Flux 31 585 Mx 315.8 µWb
Pc Coefficient 0.96 High (Stable)

Table 11: Hydrostatics and buoyancy
MP 30x6x10 / N38

Environment Effective steel pull Effect
Air (land) 20.71 kg Standard
Water (riverbed) 23.71 kg
(+3.00 kg buoyancy gain)
+14.5%
Corrosion warning: Standard nickel requires drying after every contact with moisture; lack of maintenance will lead to rust spots.
1. Vertical hold

*Caution: On a vertical surface, the magnet holds merely approx. 20-30% of its max power.

2. Steel thickness impact

*Thin metal sheet (e.g. 0.5mm PC case) significantly limits 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) = 0.96

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.

Technical and environmental data
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%
Sustainability
recyclability (EoL) 100%
recycled raw materials ~10% (pre-cons)
carbon footprint low / zredukowany
waste code (EWC) 16 02 16
Safety card (GPSR)
responsible entity
Dhit sp. z o.o.
ul. Kościuszki 6A, 05-850 Ożarów Mazowiecki
tel: +48 22 499 98 98 | e-mail: bok@dhit.pl
batch number/type
id: 030197-2026
Magnet Unit Converter
Force (pull)

Magnetic Induction

See also products

The ring magnet with a hole MP 30x6x10 / N38 is created for permanent mounting, where glue might fail or be insufficient. Thanks to the hole (often for a screw), this model enables easy screwing to wood, wall, plastic, or metal. This product with a force of 20.71 kg works great as a cabinet closure, speaker holder, or spacer element in devices.
This material behaves more like porcelain than steel, so it doesn't forgive mistakes during mounting. One turn too many can destroy the magnet, so do it slowly. It's a good idea to use a rubber spacer under the screw head, which will cushion the stresses. Remember: cracking during assembly results from material properties, not a product defect.
Moisture can penetrate micro-cracks in the coating and cause oxidation of the magnet. In the place of the mounting hole, the coating is thinner and can be damaged when tightening the screw, which will become a corrosion focus. If you must use it outside, paint it with anti-corrosion paint after mounting.
The inner hole diameter determines the maximum size of the mounting element. If the magnet does not have a chamfer (cone), we recommend using a screw with a flat or cylindrical head, or possibly using a washer. Aesthetic mounting requires selecting the appropriate head size.
It is a magnetic ring with a diameter of 30 mm and thickness 10 mm. The pulling force of this model is an impressive 20.71 kg, which translates to 203.16 N in newtons. The mounting hole diameter is precisely 6 mm.
The poles are located on the planes with holes, not on the sides of the ring. In the case of connecting two rings, make sure one is turned the right way. We do not offer paired sets with marked poles in this category, but they are easy to match manually.

Advantages and disadvantages of neodymium magnets.

Pros

Besides their remarkable magnetic power, neodymium magnets offer the following advantages:
  • They retain full power for almost 10 years – the loss is just ~1% (in theory),
  • They feature excellent resistance to magnetic field loss when exposed to external magnetic sources,
  • 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 one of their assets,
  • Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their shape) at temperatures up to 230°C and above...
  • Possibility of accurate shaping as well as adjusting to individual requirements,
  • Universal use in innovative solutions – they are used in data components, electric motors, diagnostic systems, and modern systems.
  • Compactness – despite small sizes they provide effective action, making them ideal for precision applications

Cons

Cons of neodymium magnets: tips and applications.
  • They are prone to damage 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 increases its resistance to damage
  • When exposed to high temperature, neodymium magnets experience a drop in power. Often, when the temperature exceeds 80°C, their strength decreases (depending on the size, as well as shape of the magnet). For those who need magnets for extreme conditions, we offer [AH] versions withstanding up to 230°C
  • They rust in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
  • We recommend casing - magnetic mechanism, due to difficulties in realizing threads inside the magnet and complex forms.
  • Health risk related to microscopic parts of magnets are risky, if swallowed, which becomes key in the aspect of protecting the youngest. It is also worth noting that tiny parts of these devices can disrupt the diagnostic process medical in case of swallowing.
  • Due to expensive raw materials, their price is higher than average,

Holding force characteristics

Maximum magnetic pulling forcewhat it depends on?

Holding force of 20.71 kg is a result of laboratory testing performed under standard conditions:
  • on a plate made of structural steel, perfectly concentrating the magnetic flux
  • with a thickness no less than 10 mm
  • with a surface free of scratches
  • with direct contact (without impurities)
  • for force acting at a right angle (in the magnet axis)
  • in neutral thermal conditions

Impact of factors on magnetic holding capacity in practice

Bear in mind that the magnet holding will differ influenced by elements below, in order of importance:
  • Gap between magnet and steel – every millimeter of distance (caused e.g. by varnish or unevenness) diminishes the magnet efficiency, often by half at just 0.5 mm.
  • Pull-off angle – note that the magnet has greatest strength perpendicularly. Under shear forces, the capacity drops drastically, often to levels of 20-30% of the maximum value.
  • Metal thickness – the thinner the sheet, the weaker the hold. Part of the magnetic field penetrates through instead of generating force.
  • Material type – the best choice is pure iron steel. Cast iron may generate lower lifting capacity.
  • Base smoothness – the smoother and more polished the plate, the better the adhesion and stronger the hold. Roughness creates an air distance.
  • Heat – neodymium magnets have a sensitivity to temperature. When it is hot they are weaker, and at low temperatures they can be stronger (up to a certain limit).

Holding force was tested on the plate surface of 20 mm thickness, when the force acted perpendicularly, however under attempts to slide the magnet the lifting capacity is smaller. In addition, even a minimal clearance between the magnet and the plate lowers the load capacity.

H&S for magnets
Danger to the youngest

Neodymium magnets are not intended for children. Swallowing several magnets can lead to them connecting inside the digestive tract, which constitutes a direct threat to life and requires urgent medical intervention.

Warning for allergy sufferers

Certain individuals experience a contact allergy to Ni, which is the common plating for neodymium magnets. Frequent touching might lead to skin redness. We recommend wear protective gloves.

Fire warning

Combustion risk: Neodymium dust is highly flammable. Do not process magnets without safety gear as this risks ignition.

Demagnetization risk

Avoid heat. Neodymium magnets are susceptible to heat. If you need operation above 80°C, ask us about HT versions (H, SH, UH).

Protect data

Data protection: Neodymium magnets can ruin data carriers and delicate electronics (heart implants, hearing aids, mechanical watches).

Magnets are brittle

Despite metallic appearance, the material is brittle and cannot withstand shocks. Do not hit, as the magnet may crumble into sharp, dangerous pieces.

Phone sensors

Navigation devices and smartphones are highly susceptible to magnetism. Close proximity with a strong magnet can permanently damage the sensors in your phone.

Immense force

Before use, read the rules. Uncontrolled attraction can break the magnet or hurt your hand. Be predictive.

Life threat

Warning for patients: Powerful magnets affect medical devices. Maintain at least 30 cm distance or request help to work with the magnets.

Bone fractures

Big blocks can break fingers instantly. Do not put your hand betwixt two strong magnets.

Caution! Looking for details? Check our post: Why are neodymium magnets dangerous?
Dhit sp. z o.o.

e-mail: bok@dhit.pl

tel: +48 888 99 98 98