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MP 10x7/3.5x3 / N38 - ring magnet

ring magnet

Catalog no 030180

GTIN/EAN: 5906301811978

5.00

Diameter

10 mm [±0,1 mm]

internal diameter Ø

7/3.5 mm [±0,1 mm]

Height

3 mm [±0,1 mm]

Weight

1.55 g

Magnetization Direction

↑ axial

Load capacity

1.88 kg / 18.47 N

Magnetic Induction

318.70 mT / 3187 Gs

Coating

[NiCuNi] Nickel

0.824 with VAT / pcs + price for transport

0.670 ZŁ net + 23% VAT / pcs

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Technical - MP 10x7/3.5x3 / N38 - ring magnet

Specification / characteristics - MP 10x7/3.5x3 / N38 - ring magnet

properties
properties values
Cat. no. 030180
GTIN/EAN 5906301811978
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 7/3.5 mm [±0,1 mm]
Height 3 mm [±0,1 mm]
Weight 1.55 g
Magnetization Direction ↑ axial
Load capacity ~ ? 1.88 kg / 18.47 N
Magnetic Induction ~ ? 318.70 mT / 3187 Gs
Coating [NiCuNi] Nickel
Manufacturing Tolerance ±0.1 mm

Magnetic properties of material N38

Specification / characteristics MP 10x7/3.5x3 / 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 analysis of the assembly - technical parameters

Presented data represent the outcome of a mathematical calculation. Values rely on models for the material Nd2Fe14B. Actual performance may deviate from the simulation results. Please consider these data as a reference point when designing systems.

Table 1: Static force (force vs distance) - interaction chart
MP 10x7/3.5x3 / N38

Distance (mm) Induction (Gauss) / mT Pull Force (kg/lbs/g/N) Risk Status
0 mm 2813 Gs
281.3 mT
1.88 kg / 4.14 LBS
1880.0 g / 18.4 N
safe
1 mm 2373 Gs
237.3 mT
1.34 kg / 2.95 LBS
1338.1 g / 13.1 N
safe
2 mm 1870 Gs
187.0 mT
0.83 kg / 1.83 LBS
830.9 g / 8.2 N
safe
3 mm 1416 Gs
141.6 mT
0.48 kg / 1.05 LBS
476.6 g / 4.7 N
safe
5 mm 785 Gs
78.5 mT
0.15 kg / 0.32 LBS
146.4 g / 1.4 N
safe
10 mm 214 Gs
21.4 mT
0.01 kg / 0.02 LBS
10.9 g / 0.1 N
safe
15 mm 81 Gs
8.1 mT
0.00 kg / 0.00 LBS
1.6 g / 0.0 N
safe
20 mm 38 Gs
3.8 mT
0.00 kg / 0.00 LBS
0.3 g / 0.0 N
safe
30 mm 12 Gs
1.2 mT
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
safe
50 mm 3 Gs
0.3 mT
0.00 kg / 0.00 LBS
0.0 g / 0.0 N
safe

Table 2: Slippage force (vertical surface)
MP 10x7/3.5x3 / N38

Distance (mm) Friction coefficient Pull Force (kg/lbs/g/N)
0 mm Stal (~0.2) 0.38 kg / 0.83 LBS
376.0 g / 3.7 N
1 mm Stal (~0.2) 0.27 kg / 0.59 LBS
268.0 g / 2.6 N
2 mm Stal (~0.2) 0.17 kg / 0.37 LBS
166.0 g / 1.6 N
3 mm Stal (~0.2) 0.10 kg / 0.21 LBS
96.0 g / 0.9 N
5 mm Stal (~0.2) 0.03 kg / 0.07 LBS
30.0 g / 0.3 N
10 mm Stal (~0.2) 0.00 kg / 0.00 LBS
2.0 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: Wall mounting (sliding) - behavior on slippery surfaces
MP 10x7/3.5x3 / N38

Surface type Friction coefficient / % Mocy Max load (kg/lbs/g/N)
Raw steel
µ = 0.3 30% Nominalnej Siły
0.56 kg / 1.24 LBS
564.0 g / 5.5 N
Painted steel (standard)
µ = 0.2 20% Nominalnej Siły
0.38 kg / 0.83 LBS
376.0 g / 3.7 N
Oily/slippery steel
µ = 0.1 10% Nominalnej Siły
0.19 kg / 0.41 LBS
188.0 g / 1.8 N
Magnet with anti-slip rubber
µ = 0.5 50% Nominalnej Siły
0.94 kg / 2.07 LBS
940.0 g / 9.2 N

Table 4: Steel thickness (saturation) - sheet metal selection
MP 10x7/3.5x3 / N38

Steel thickness (mm) % power Real pull force (kg/lbs/g/N)
0.5 mm
10%
0.19 kg / 0.41 LBS
188.0 g / 1.8 N
1 mm
25%
0.47 kg / 1.04 LBS
470.0 g / 4.6 N
2 mm
50%
0.94 kg / 2.07 LBS
940.0 g / 9.2 N
3 mm
75%
1.41 kg / 3.11 LBS
1410.0 g / 13.8 N
5 mm
100%
1.88 kg / 4.14 LBS
1880.0 g / 18.4 N
10 mm
100%
1.88 kg / 4.14 LBS
1880.0 g / 18.4 N
11 mm
100%
1.88 kg / 4.14 LBS
1880.0 g / 18.4 N
12 mm
100%
1.88 kg / 4.14 LBS
1880.0 g / 18.4 N

Table 5: Thermal stability (stability) - thermal limit
MP 10x7/3.5x3 / N38

Ambient temp. (°C) Power loss Remaining pull (kg/lbs/g/N) Status
20 °C 0.0% 1.88 kg / 4.14 LBS
1880.0 g / 18.4 N
OK
40 °C -2.2% 1.84 kg / 4.05 LBS
1838.6 g / 18.0 N
OK
60 °C -4.4% 1.80 kg / 3.96 LBS
1797.3 g / 17.6 N
80 °C -6.6% 1.76 kg / 3.87 LBS
1755.9 g / 17.2 N
100 °C -28.8% 1.34 kg / 2.95 LBS
1338.6 g / 13.1 N

Table 6: Magnet-Magnet interaction (repulsion) - field range
MP 10x7/3.5x3 / N38

Gap (mm) Attraction (kg/lbs) (N-S) Sliding Force (kg/lbs/g/N) Repulsion (kg/lbs) (N-N)
0 mm 2.86 kg / 6.30 LBS
4 419 Gs
0.43 kg / 0.95 LBS
429 g / 4.2 N
N/A
1 mm 2.46 kg / 5.43 LBS
5 224 Gs
0.37 kg / 0.81 LBS
370 g / 3.6 N
2.22 kg / 4.89 LBS
~0 Gs
2 mm 2.03 kg / 4.49 LBS
4 747 Gs
0.31 kg / 0.67 LBS
305 g / 3.0 N
1.83 kg / 4.04 LBS
~0 Gs
3 mm 1.62 kg / 3.58 LBS
4 242 Gs
0.24 kg / 0.54 LBS
244 g / 2.4 N
1.46 kg / 3.22 LBS
~0 Gs
5 mm 0.96 kg / 2.12 LBS
3 266 Gs
0.14 kg / 0.32 LBS
144 g / 1.4 N
0.87 kg / 1.91 LBS
~0 Gs
10 mm 0.22 kg / 0.49 LBS
1 570 Gs
0.03 kg / 0.07 LBS
33 g / 0.3 N
0.20 kg / 0.44 LBS
~0 Gs
20 mm 0.02 kg / 0.04 LBS
429 Gs
0.00 kg / 0.01 LBS
2 g / 0.0 N
0.01 kg / 0.03 LBS
~0 Gs
50 mm 0.00 kg / 0.00 LBS
41 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
25 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
16 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
11 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
8 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
6 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 10x7/3.5x3 / N38

Object / Device Limit (Gauss) / mT Safe distance
Pacemaker 5 Gs (0.5 mT) 4.5 cm
Hearing aid 10 Gs (1.0 mT) 3.5 cm
Mechanical watch 20 Gs (2.0 mT) 3.0 cm
Phone / Smartphone 40 Gs (4.0 mT) 2.0 cm
Car key 50 Gs (5.0 mT) 2.0 cm
Payment card 400 Gs (40.0 mT) 1.0 cm
HDD hard drive 600 Gs (60.0 mT) 1.0 cm

Table 8: Dynamics (kinetic energy) - collision effects
MP 10x7/3.5x3 / N38

Start from (mm) Speed (km/h) Energy (J) Predicted outcome
10 mm 35.25 km/h
(9.79 m/s)
0.07 J
30 mm 60.84 km/h
(16.90 m/s)
0.22 J
50 mm 78.54 km/h
(21.82 m/s)
0.37 J
100 mm 111.07 km/h
(30.85 m/s)
0.74 J

Table 9: Corrosion resistance
MP 10x7/3.5x3 / 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: Electrical data (Flux)
MP 10x7/3.5x3 / N38

Parameter Value SI Unit / Description
Magnetic Flux 1 899 Mx 19.0 µWb
Pc Coefficient 0.37 Low (Flat)

Table 11: Submerged application
MP 10x7/3.5x3 / N38

Environment Effective steel pull Effect
Air (land) 1.88 kg Standard
Water (riverbed) 2.15 kg
(+0.27 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. Shear force

*Note: On a vertical wall, the magnet retains only a fraction of its perpendicular strength.

2. Efficiency vs thickness

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

3. Heat tolerance

*For N38 material, the critical limit is 80°C.

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

chart generated for the permeance coefficient Pc (Permeance Coefficient) = 0.37

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.

Engineering data and GPSR
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%
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: 030180-2026
Magnet Unit Converter
Force (pull)

Magnetic Induction

Other proposals

It is ideally suited for places where solid attachment of the magnet to the substrate is required without the risk of detachment. Mounting is clean and reversible, unlike gluing. 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 10x7/3.5x3 / N38. Neodymium magnets are sintered ceramics, which means they are very brittle and inelastic. 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. Damage to the protective layer during assembly is the most common cause of rusting. 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. 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.
It is a magnetic ring with a diameter of 10 mm and thickness 3 mm. The pulling force of this model is an impressive 1.88 kg, which translates to 18.47 N in newtons. The mounting hole diameter is precisely 7/3.5 mm.
These magnets are magnetized axially (through the thickness), which means one flat side is the N pole and the other is S. In the case of connecting two rings, make sure one is turned the right way. When ordering a larger quantity, magnets are usually packed in stacks, where they are already naturally paired.

Strengths as well as weaknesses of neodymium magnets.

Advantages

In addition to their long-term stability, neodymium magnets provide the following advantages:
  • They retain attractive force for almost ten years – the drop is just ~1% (according to analyses),
  • Magnets effectively resist against demagnetization caused by ambient magnetic noise,
  • The use of an shiny coating of noble metals (nickel, gold, silver) causes the element to have aesthetics,
  • They feature high magnetic induction at the operating surface, which improves attraction properties,
  • 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 adapting to defined conditions,
  • Fundamental importance in future technologies – they serve a role in computer drives, electromotive mechanisms, precision medical tools, also multitasking production systems.
  • Thanks to concentrated force, small magnets offer high operating force, occupying minimum space,

Weaknesses

Problematic aspects of neodymium magnets: weaknesses and usage proposals
  • At very strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
  • NdFeB magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of power (a factor is the shape as well as 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
  • Due to the susceptibility of magnets to corrosion in a humid environment, we suggest using waterproof magnets made of rubber, plastic or other material stable to moisture, when using outdoors
  • Due to limitations in creating nuts and complicated shapes in magnets, we propose using a housing - magnetic holder.
  • Potential hazard related to microscopic parts of magnets pose a threat, in case of ingestion, which becomes key in the context of child safety. Additionally, tiny parts of these magnets are able to be problematic in diagnostics medical after entering the body.
  • With large orders the cost of neodymium magnets can be a barrier,

Pull force analysis

Maximum lifting force for a neodymium magnet – what it depends on?

The load parameter shown represents the maximum value, obtained under optimal environment, specifically:
  • on a base made of structural steel, perfectly concentrating the magnetic field
  • possessing a thickness of min. 10 mm to ensure full flux closure
  • characterized by even structure
  • under conditions of ideal adhesion (metal-to-metal)
  • for force acting at a right angle (in the magnet axis)
  • at temperature approx. 20 degrees Celsius

Determinants of practical lifting force of a magnet

Holding efficiency is influenced by specific conditions, mainly (from priority):
  • Gap between surfaces – every millimeter of separation (caused e.g. by veneer or unevenness) drastically reduces the magnet efficiency, often by half at just 0.5 mm.
  • Force direction – declared lifting capacity refers to detachment vertically. When attempting to slide, the magnet exhibits much less (typically approx. 20-30% of maximum force).
  • Element thickness – for full efficiency, the steel must be sufficiently thick. Thin sheet restricts the lifting capacity (the magnet "punches through" it).
  • Steel grade – the best choice is pure iron steel. Stainless steels may generate lower lifting capacity.
  • Base smoothness – the smoother and more polished the plate, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
  • Temperature – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

Lifting capacity testing was performed on a smooth plate of optimal thickness, under perpendicular forces, in contrast under shearing force the load capacity is reduced by as much as 5 times. Additionally, even a small distance between the magnet’s surface and the plate reduces the lifting capacity.

Warnings
ICD Warning

Patients with a heart stimulator have to keep an absolute distance from magnets. The magnetism can disrupt the operation of the implant.

Power loss in heat

Keep cool. NdFeB magnets are susceptible to temperature. If you need operation above 80°C, look for special high-temperature series (H, SH, UH).

Electronic devices

Do not bring magnets close to a wallet, computer, or TV. The magnetism can irreversibly ruin these devices and wipe information from cards.

Protective goggles

Beware of splinters. Magnets can explode upon violent connection, launching sharp fragments into the air. We recommend safety glasses.

Bodily injuries

Large magnets can crush fingers instantly. Do not put your hand betwixt two strong magnets.

No play value

Strictly store magnets away from children. Choking hazard is significant, and the effects of magnets clamping inside the body are tragic.

Keep away from electronics

Note: neodymium magnets generate a field that confuses precision electronics. Keep a separation from your mobile, device, and navigation systems.

Sensitization to coating

Studies show that nickel (the usual finish) is a common allergen. If you have an allergy, refrain from touching magnets with bare hands and choose coated magnets.

Dust is flammable

Dust produced during grinding of magnets is flammable. Avoid drilling into magnets without proper cooling and knowledge.

Do not underestimate power

Before use, read the rules. Sudden snapping can destroy the magnet or hurt your hand. Think ahead.

Safety First! Need more info? Check our post: Are neodymium magnets dangerous?
Dhit sp. z o.o.

e-mail: bok@dhit.pl

tel: +48 888 99 98 98