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MP 10x4.3x4 / N38 - ring magnet

ring magnet

Catalog no 030178

GTIN/EAN: 5906301811954

5.00

Diameter

10 mm [±0,1 mm]

internal diameter Ø

4.3 mm [±0,1 mm]

Height

4 mm [±0,1 mm]

Weight

1.92 g

Magnetization Direction

↑ axial

Load capacity

2.28 kg / 22.35 N

Magnetic Induction

386.91 mT / 3869 Gs

Coating

[NiCuNi] Nickel

1.045 with VAT / pcs + price for transport

0.850 ZŁ net + 23% VAT / pcs

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Technical details - MP 10x4.3x4 / N38 - ring magnet

Specification / characteristics - MP 10x4.3x4 / N38 - ring magnet

properties
properties values
Cat. no. 030178
GTIN/EAN 5906301811954
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 10 mm [±0,1 mm]
internal diameter Ø 4.3 mm [±0,1 mm]
Height 4 mm [±0,1 mm]
Weight 1.92 g
Magnetization Direction ↑ axial
Load capacity ~ ? 2.28 kg / 22.35 N
Magnetic Induction ~ ? 386.91 mT / 3869 Gs
Coating [NiCuNi] Nickel
Manufacturing Tolerance ±0.1 mm

Magnetic properties of material N38

Specification / characteristics MP 10x4.3x4 / 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 magnet - technical parameters

These information represent the result of a mathematical calculation. Values rely on models for the class Nd2Fe14B. Real-world performance may differ from theoretical values. Use these data as a preliminary roadmap when designing systems.

Table 1: Static force (pull vs gap) - power drop
MP 10x4.3x4 / N38

Distance (mm) Induction (Gauss) / mT Pull Force (kg/lbs/g/N) Risk Status
0 mm 6115 Gs
611.5 mT
2.28 kg / 5.03 lbs
2280.0 g / 22.4 N
warning
1 mm 4915 Gs
491.5 mT
1.47 kg / 3.25 lbs
1473.3 g / 14.5 N
safe
2 mm 3833 Gs
383.3 mT
0.90 kg / 1.97 lbs
895.7 g / 8.8 N
safe
3 mm 2949 Gs
294.9 mT
0.53 kg / 1.17 lbs
530.3 g / 5.2 N
safe
5 mm 1761 Gs
176.1 mT
0.19 kg / 0.42 lbs
189.1 g / 1.9 N
safe
10 mm 612 Gs
61.2 mT
0.02 kg / 0.05 lbs
22.8 g / 0.2 N
safe
15 mm 284 Gs
28.4 mT
0.00 kg / 0.01 lbs
4.9 g / 0.0 N
safe
20 mm 157 Gs
15.7 mT
0.00 kg / 0.00 lbs
1.5 g / 0.0 N
safe
30 mm 64 Gs
6.4 mT
0.00 kg / 0.00 lbs
0.3 g / 0.0 N
safe
50 mm 19 Gs
1.9 mT
0.00 kg / 0.00 lbs
0.0 g / 0.0 N
safe

Table 2: Vertical capacity (vertical surface)
MP 10x4.3x4 / N38

Distance (mm) Friction coefficient Pull Force (kg/lbs/g/N)
0 mm Stal (~0.2) 0.46 kg / 1.01 lbs
456.0 g / 4.5 N
1 mm Stal (~0.2) 0.29 kg / 0.65 lbs
294.0 g / 2.9 N
2 mm Stal (~0.2) 0.18 kg / 0.40 lbs
180.0 g / 1.8 N
3 mm Stal (~0.2) 0.11 kg / 0.23 lbs
106.0 g / 1.0 N
5 mm Stal (~0.2) 0.04 kg / 0.08 lbs
38.0 g / 0.4 N
10 mm Stal (~0.2) 0.00 kg / 0.01 lbs
4.0 g / 0.0 N
15 mm Stal (~0.2) 0.00 kg / 0.00 lbs
0.0 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 (sliding) - vertical pull
MP 10x4.3x4 / N38

Surface type Friction coefficient / % Mocy Max load (kg/lbs/g/N)
Raw steel
µ = 0.3 30% Nominalnej Siły
0.68 kg / 1.51 lbs
684.0 g / 6.7 N
Painted steel (standard)
µ = 0.2 20% Nominalnej Siły
0.46 kg / 1.01 lbs
456.0 g / 4.5 N
Oily/slippery steel
µ = 0.1 10% Nominalnej Siły
0.23 kg / 0.50 lbs
228.0 g / 2.2 N
Magnet with anti-slip rubber
µ = 0.5 50% Nominalnej Siły
1.14 kg / 2.51 lbs
1140.0 g / 11.2 N

Table 4: Material efficiency (saturation) - power losses
MP 10x4.3x4 / N38

Steel thickness (mm) % power Real pull force (kg/lbs/g/N)
0.5 mm
10%
0.23 kg / 0.50 lbs
228.0 g / 2.2 N
1 mm
25%
0.57 kg / 1.26 lbs
570.0 g / 5.6 N
2 mm
50%
1.14 kg / 2.51 lbs
1140.0 g / 11.2 N
3 mm
75%
1.71 kg / 3.77 lbs
1710.0 g / 16.8 N
5 mm
100%
2.28 kg / 5.03 lbs
2280.0 g / 22.4 N
10 mm
100%
2.28 kg / 5.03 lbs
2280.0 g / 22.4 N
11 mm
100%
2.28 kg / 5.03 lbs
2280.0 g / 22.4 N
12 mm
100%
2.28 kg / 5.03 lbs
2280.0 g / 22.4 N

Table 5: Thermal resistance (material behavior) - power drop
MP 10x4.3x4 / N38

Ambient temp. (°C) Power loss Remaining pull (kg/lbs/g/N) Status
20 °C 0.0% 2.28 kg / 5.03 lbs
2280.0 g / 22.4 N
OK
40 °C -2.2% 2.23 kg / 4.92 lbs
2229.8 g / 21.9 N
OK
60 °C -4.4% 2.18 kg / 4.81 lbs
2179.7 g / 21.4 N
OK
80 °C -6.6% 2.13 kg / 4.69 lbs
2129.5 g / 20.9 N
100 °C -28.8% 1.62 kg / 3.58 lbs
1623.4 g / 15.9 N

Table 6: Two magnets (attraction) - field range
MP 10x4.3x4 / N38

Gap (mm) Attraction (kg/lbs) (N-S) Sliding Force (kg/lbs/g/N) Repulsion (kg/lbs) (N-N)
0 mm 12.93 kg / 28.50 lbs
6 169 Gs
1.94 kg / 4.27 lbs
1939 g / 19.0 N
N/A
1 mm 10.50 kg / 23.16 lbs
11 025 Gs
1.58 kg / 3.47 lbs
1576 g / 15.5 N
9.45 kg / 20.84 lbs
~0 Gs
2 mm 8.35 kg / 18.41 lbs
9 831 Gs
1.25 kg / 2.76 lbs
1253 g / 12.3 N
7.52 kg / 16.57 lbs
~0 Gs
3 mm 6.55 kg / 14.43 lbs
8 703 Gs
0.98 kg / 2.17 lbs
982 g / 9.6 N
5.89 kg / 12.99 lbs
~0 Gs
5 mm 3.91 kg / 8.63 lbs
6 729 Gs
0.59 kg / 1.29 lbs
587 g / 5.8 N
3.52 kg / 7.76 lbs
~0 Gs
10 mm 1.07 kg / 2.36 lbs
3 522 Gs
0.16 kg / 0.35 lbs
161 g / 1.6 N
0.96 kg / 2.13 lbs
~0 Gs
20 mm 0.13 kg / 0.29 lbs
1 223 Gs
0.02 kg / 0.04 lbs
19 g / 0.2 N
0.12 kg / 0.26 lbs
~0 Gs
50 mm 0.00 kg / 0.01 lbs
194 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
129 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
91 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
66 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
50 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
39 Gs
0.00 kg / 0.00 lbs
0 g / 0.0 N
0.00 kg / 0.00 lbs
~0 Gs

Table 7: Safety (HSE) (implants) - warnings
MP 10x4.3x4 / N38

Object / Device Limit (Gauss) / mT Safe distance
Pacemaker 5 Gs (0.5 mT) 9.0 cm
Hearing aid 10 Gs (1.0 mT) 7.0 cm
Mechanical watch 20 Gs (2.0 mT) 5.0 cm
Phone / Smartphone 40 Gs (4.0 mT) 4.0 cm
Car key 50 Gs (5.0 mT) 3.5 cm
Payment card 400 Gs (40.0 mT) 1.5 cm
HDD hard drive 600 Gs (60.0 mT) 1.5 cm

Table 8: Dynamics (cracking risk) - warning
MP 10x4.3x4 / N38

Start from (mm) Speed (km/h) Energy (J) Predicted outcome
10 mm 34.97 km/h
(9.71 m/s)
0.09 J
30 mm 60.20 km/h
(16.72 m/s)
0.27 J
50 mm 77.71 km/h
(21.59 m/s)
0.45 J
100 mm 109.90 km/h
(30.53 m/s)
0.89 J

Table 9: Anti-corrosion coating durability
MP 10x4.3x4 / 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 10x4.3x4 / N38

Parameter Value SI Unit / Description
Magnetic Flux 4 017 Mx 40.2 µWb
Pc Coefficient 1.44 High (Stable)

Table 11: Physics of underwater searching
MP 10x4.3x4 / N38

Environment Effective steel pull Effect
Air (land) 2.28 kg Standard
Water (riverbed) 2.61 kg
(+0.33 kg buoyancy gain)
+14.5%
Warning: This magnet has a standard nickel coating. After use in water, it must be dried and maintained immediately, otherwise it will rust!
1. Wall mount (shear)

*Warning: On a vertical wall, the magnet holds just approx. 20-30% of its nominal pull.

2. Plate thickness effect

*Thin steel (e.g. 0.5mm PC case) drastically reduces the holding force.

3. Heat tolerance

*For N38 grade, the max working temp is 80°C.

4. Demagnetization curve and operating point (B-H)

chart generated for the permeance coefficient Pc (Permeance Coefficient) = 1.44

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 specification and ecology
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%
Environmental data
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: 030178-2026
Measurement Calculator
Magnet pull force

Magnetic Field

Other offers

The ring magnet with a hole MP 10x4.3x4 / N38 is created for permanent mounting, where glue might fail or be insufficient. Thanks to the hole (often for a screw), this model enables quick installation to wood, wall, plastic, or metal. It is also often used in advertising for fixing signs and in workshops for organizing tools.
This is a crucial issue when working with model MP 10x4.3x4 / N38. Neodymium magnets are sintered ceramics, which means they are very brittle and inelastic. When tightening the screw, you must maintain great sensitivity. We recommend tightening manually with a screwdriver, not an impact driver, because excessive force will cause the ring to crack. The flat screw head should evenly press the magnet. 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. Damage to the protective layer during assembly is the most common cause of rusting. This product is dedicated for indoor use. For outdoor applications, we recommend choosing magnets in hermetic housing or additional protection with varnish.
A screw or bolt with a thread diameter smaller than 4.3 mm fits this model. 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. Always check that the screw head is not larger than the outer diameter of the magnet (10 mm), so it doesn't protrude beyond the outline.
The presented product is a ring magnet with dimensions Ø10 mm (outer diameter) and height 4 mm. The key parameter here is the holding force amounting to approximately 2.28 kg (force ~22.35 N). The product has a [NiCuNi] coating and is made of NdFeB material. Inner hole dimension: 4.3 mm.
The poles are located on the planes with holes, not on the sides of the ring. If you want two such magnets screwed with cones facing each other (faces) to attract, you must connect them with opposite poles (N to S). We do not offer paired sets with marked poles in this category, but they are easy to match manually.

Strengths as well as weaknesses of Nd2Fe14B magnets.

Strengths

In addition to their pulling strength, neodymium magnets provide the following advantages:
  • They do not lose strength, even during approximately ten years – the drop in lifting capacity is only ~1% (theoretically),
  • Magnets effectively resist against demagnetization caused by foreign field sources,
  • In other words, due to the shiny finish of nickel, the element becomes visually attractive,
  • The surface of neodymium magnets generates a concentrated magnetic field – this is a distinguishing feature,
  • Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the form) even at high temperatures reaching 230°C or more...
  • Possibility of detailed shaping as well as adjusting to specific needs,
  • Key role in modern technologies – they are used in hard drives, electromotive mechanisms, medical devices, as well as multitasking production systems.
  • Relatively small size with high pulling force – neodymium magnets offer strong magnetic field in tiny dimensions, which enables their usage in miniature devices

Weaknesses

Drawbacks and weaknesses of neodymium magnets and proposals for their use:
  • They are fragile upon heavy impacts. To avoid cracks, it is worth protecting magnets in special housings. Such protection not only shields the magnet but also improves its resistance to damage
  • Neodymium magnets lose their strength 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
  • They rust in a humid environment. For use outdoors we recommend using waterproof magnets e.g. in rubber, plastic
  • Limited ability of making nuts in the magnet and complicated shapes - recommended is cover - magnet mounting.
  • Health risk to health – tiny shards of magnets are risky, in case of ingestion, which becomes key in the context of child safety. Furthermore, small elements of these devices can disrupt the diagnostic process 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 magnetwhat contributes to it?

Breakaway force was defined for the most favorable conditions, assuming:
  • with the use of a yoke made of special test steel, guaranteeing full magnetic saturation
  • possessing a thickness of at least 10 mm to avoid saturation
  • with a surface cleaned and smooth
  • without any air gap between the magnet and steel
  • under vertical force direction (90-degree angle)
  • in neutral thermal conditions

Lifting capacity in practice – influencing factors

Please note that the application force will differ influenced by the following factors, starting with the most relevant:
  • Space between magnet and steel – even a fraction of a millimeter of distance (caused e.g. by veneer or unevenness) drastically reduces the pulling force, often by half at just 0.5 mm.
  • Force direction – declared lifting capacity refers to pulling vertically. When attempting to slide, the magnet exhibits significantly lower power (often approx. 20-30% of nominal force).
  • Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet limits the attraction force (the magnet "punches through" it).
  • Steel type – low-carbon steel attracts best. Alloy admixtures lower magnetic properties and holding force.
  • Base smoothness – the more even the surface, the larger the contact zone and stronger the hold. Roughness creates an air distance.
  • Thermal environment – heating the magnet causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

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 load capacity is reduced by as much as 75%. Additionally, even a small distance between the magnet and the plate reduces the lifting capacity.

Precautions when working with neodymium magnets
Sensitization to coating

A percentage of the population suffer from a contact allergy to nickel, which is the common plating for NdFeB magnets. Frequent touching can result in an allergic reaction. We suggest wear protective gloves.

Eye protection

Neodymium magnets are sintered ceramics, meaning they are fragile like glass. Clashing of two magnets will cause them breaking into shards.

Phone sensors

An intense magnetic field disrupts the operation of magnetometers in smartphones and GPS navigation. Keep magnets near a device to avoid breaking the sensors.

Adults only

NdFeB magnets are not intended for children. Swallowing a few magnets may result in them connecting inside the digestive tract, which constitutes a severe health hazard and necessitates urgent medical intervention.

Safe operation

Handle magnets consciously. Their powerful strength can shock even professionals. Stay alert and do not underestimate their force.

Power loss in heat

Monitor thermal conditions. Heating the magnet to high heat will ruin its properties and pulling force.

Danger to pacemakers

Patients with a ICD have to keep an absolute distance from magnets. The magnetic field can disrupt the functioning of the life-saving device.

Electronic hazard

Intense magnetic fields can corrupt files on credit cards, HDDs, and storage devices. Stay away of min. 10 cm.

Fire warning

Machining of NdFeB material carries a risk of fire hazard. Neodymium dust reacts violently with oxygen and is difficult to extinguish.

Crushing risk

Big blocks can crush fingers in a fraction of a second. Under no circumstances put your hand between two attracting surfaces.

Caution! Learn more about hazards in the article: Magnet Safety Guide.