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MP 25x7.5/4.5x5 / N38 - ring magnet

Name: Dhit sp. z o.o.
Address: Kościuszki 6A, Ożarów Mazowiecki, Poland, 05-850, PL
Telephone: +48 22 499 98 98
Price range: PLN 1-6500
Rating: 5

ring magnet

Catalog no 030194

GTIN/EAN: 5906301812111

5.00

Diameter

25 mm [±0,1 mm]

internal diameter Ø

7.5/4.5 mm [±0,1 mm]

Height

5 mm [±0,1 mm]

Weight

17.81 g

Magnetization Direction

↑ axial

Load capacity

7.72 kg / 75.69 N

Magnetic Induction

230.20 mT / 2302 Gs

Coating

[NiCuNi] Nickel

technical specifications »

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Technical of the product - MP 25x7.5/4.5x5 / N38 - ring magnet

Specification / characteristics - MP 25x7.5/4.5x5 / N38 - ring magnet

properties

properties	values
Cat. no.	030194
GTIN/EAN	5906301812111
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	25 mm [±0,1 mm]
internal diameter Ø	7.5/4.5 mm [±0,1 mm]
Height	5 mm [±0,1 mm]
Weight	17.81 g
Magnetization Direction	↑ axial
Load capacity ~ ?	7.72 kg / 75.69 N
Magnetic Induction ~ ?	230.20 mT / 2302 Gs
Coating	[NiCuNi] Nickel
Manufacturing Tolerance	±0.1 mm

Magnetic properties of material N38

Specification / characteristics MP 25x7.5/4.5x5 / 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

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 product - report

These data are the result of a physical simulation. Values were calculated on models for the material Nd₂Fe₁₄B. Real-world conditions might slightly differ. Please consider these data as a preliminary roadmap during assembly planning.

Table 1: Static force (force vs distance) - power drop
MP 25x7.5/4.5x5 / N38

Distance (mm)	Induction (Gauss) / mT	Pull Force (kg/lbs/g/N)	Risk Status
0 mm	1995 Gs 199.5 mT	7.72 kg / 17.02 pounds 7720.0 g / 75.7 N	warning
1 mm	1906 Gs 190.6 mT	7.05 kg / 15.54 pounds 7049.4 g / 69.2 N	warning
2 mm	1793 Gs 179.3 mT	6.24 kg / 13.75 pounds 6236.8 g / 61.2 N	warning
3 mm	1664 Gs 166.4 mT	5.37 kg / 11.84 pounds 5368.9 g / 52.7 N	warning
5 mm	1385 Gs 138.5 mT	3.72 kg / 8.21 pounds 3722.8 g / 36.5 N	warning
10 mm	788 Gs 78.8 mT	1.20 kg / 2.65 pounds 1203.8 g / 11.8 N	safe
15 mm	437 Gs 43.7 mT	0.37 kg / 0.82 pounds 370.3 g / 3.6 N	safe
20 mm	253 Gs 25.3 mT	0.12 kg / 0.27 pounds 124.5 g / 1.2 N	safe
30 mm	101 Gs 10.1 mT	0.02 kg / 0.04 pounds 19.8 g / 0.2 N	safe
50 mm	27 Gs 2.7 mT	0.00 kg / 0.00 pounds 1.4 g / 0.0 N	safe

Pulling power decreases significantly per each millimeter of spacing. Remember that even a very thin break (e.g., dirt, paint, veneer) strongly reduces the pull force. Neodymiums work most effectively in perfect adhesion; distance kills the force. Analyze how flashily the load capacity fall, when the magnet does not adhere directly to the steel surface. When designing the arrangement, eliminate unnecessary gaps.

Table 2: Shear force (wall)
MP 25x7.5/4.5x5 / N38

Distance (mm)	Friction coefficient	Pull Force (kg/lbs/g/N)
0 mm	Stal (~0.2)	1.54 kg / 3.40 pounds 1544.0 g / 15.1 N
1 mm	Stal (~0.2)	1.41 kg / 3.11 pounds 1410.0 g / 13.8 N
2 mm	Stal (~0.2)	1.25 kg / 2.75 pounds 1248.0 g / 12.2 N
3 mm	Stal (~0.2)	1.07 kg / 2.37 pounds 1074.0 g / 10.5 N
5 mm	Stal (~0.2)	0.74 kg / 1.64 pounds 744.0 g / 7.3 N
10 mm	Stal (~0.2)	0.24 kg / 0.53 pounds 240.0 g / 2.4 N
15 mm	Stal (~0.2)	0.07 kg / 0.16 pounds 74.0 g / 0.7 N
20 mm	Stal (~0.2)	0.02 kg / 0.05 pounds 24.0 g / 0.2 N
30 mm	Stal (~0.2)	0.00 kg / 0.01 pounds 4.0 g / 0.0 N
50 mm	Stal (~0.2)	0.00 kg / 0.00 pounds 0.0 g / 0.0 N

This section defines the estimated shear load sufficient to initiate the slippage of the magnet down along a upright steel plate (assuming typical friction coefficient). This parameter is a function of the distance between the magnet and the surface.

Table 3: Wall mounting (sliding) - vertical pull
MP 25x7.5/4.5x5 / N38

Surface type	Friction coefficient / % Mocy	Max load (kg/lbs/g/N)
Raw steel	µ = 0.3 30% Nominalnej Siły	2.32 kg / 5.11 pounds 2316.0 g / 22.7 N
Painted steel (standard)	µ = 0.2 20% Nominalnej Siły	1.54 kg / 3.40 pounds 1544.0 g / 15.1 N
Oily/slippery steel	µ = 0.1 10% Nominalnej Siły	0.77 kg / 1.70 pounds 772.0 g / 7.6 N
Magnet with anti-slip rubber	µ = 0.5 50% Nominalnej Siły	3.86 kg / 8.51 pounds 3860.0 g / 37.9 N

When mounting a magnet on a upright surface (e.g., a board), it you can count on only approx. 1/5 of its nominal power. Gravitational force and a low friction coefficient mean that products move down easier than they pop off the substrate. Want to create a hanger? Note that the sliding force is much weaker than the perpendicular breakaway force. On a painted metal, the element will slip down under a noticeably lighter cargo. Application of an anti-slip coating can drastically increase the grip.

Table 4: Steel thickness (substrate influence) - power losses
MP 25x7.5/4.5x5 / N38

Steel thickness (mm)	% power	Real pull force (kg/lbs/g/N)
0.5 mm	10%	0.77 kg / 1.70 pounds 772.0 g / 7.6 N
1 mm	25%	1.93 kg / 4.25 pounds 1930.0 g / 18.9 N
2 mm	50%	3.86 kg / 8.51 pounds 3860.0 g / 37.9 N
3 mm	75%	5.79 kg / 12.76 pounds 5790.0 g / 56.8 N
5 mm	100%	7.72 kg / 17.02 pounds 7720.0 g / 75.7 N
10 mm	100%	7.72 kg / 17.02 pounds 7720.0 g / 75.7 N
11 mm	100%	7.72 kg / 17.02 pounds 7720.0 g / 75.7 N
12 mm	100%	7.72 kg / 17.02 pounds 7720.0 g / 75.7 N

A thin metal plate cannot conduct the full magnetic flux, which wastes potential of the magnet. If you attach a powerful product to a too thin substrate, the magnetism will penetrate right through and the attraction force will be weaker. To utilize full efficiency of this magnet's potential, you require a sufficiently solid piece of metal. The saturation phenomenon causes that on sheet metal structures (e.g., appliance housings), the product shows lower pull force. We recommend selecting the steel dimension according to the table below.

Table 5: Thermal resistance (stability) - thermal limit
MP 25x7.5/4.5x5 / N38

Ambient temp. (°C)	Power loss	Remaining pull (kg/lbs/g/N)	Status
20 °C	0.0%	7.72 kg / 17.02 pounds 7720.0 g / 75.7 N	OK
40 °C	-2.2%	7.55 kg / 16.65 pounds 7550.2 g / 74.1 N	OK
60 °C	-4.4%	7.38 kg / 16.27 pounds 7380.3 g / 72.4 N
80 °C	-6.6%	7.21 kg / 15.90 pounds 7210.5 g / 70.7 N
100 °C	-28.8%	5.50 kg / 12.12 pounds 5496.6 g / 53.9 N

Classic neodymiums lose parameters past the thermal threshold. Protect against heat – heat can permanently destroy this magnet. With every degree above norm, the neodymium's capacity temporarily decreases. Refrain from using this magnet near heat sources higher than its safe range. Too high temperature will cause destruction of magnetic properties.

*Important note: Temperature resistance is determined by both grade, and the Permeance Coefficient Pc. Low-profile magnets (pancake types) risk losing magnetic properties sooner compared to rod magnets. The danger warning in the table indicates permanent field degradation for this specific geometry.

Table 6: Magnet-Magnet interaction (attraction) - forces in the system
MP 25x7.5/4.5x5 / N38

Gap (mm)	Attraction (kg/lbs) (N-S)	Lateral Force (kg/lbs/g/N)	Repulsion (kg/lbs) (N-N)
0 mm	9.91 kg / 21.84 pounds 3 484 Gs	1.49 kg / 3.28 pounds 1486 g / 14.6 N	N/A
1 mm	9.51 kg / 20.96 pounds 3 909 Gs	1.43 kg / 3.14 pounds 1426 g / 14.0 N	8.56 kg / 18.87 pounds ~0 Gs
2 mm	9.05 kg / 19.94 pounds 3 813 Gs	1.36 kg / 2.99 pounds 1357 g / 13.3 N	8.14 kg / 17.95 pounds ~0 Gs
3 mm	8.54 kg / 18.83 pounds 3 705 Gs	1.28 kg / 2.82 pounds 1281 g / 12.6 N	7.69 kg / 16.94 pounds ~0 Gs
5 mm	7.45 kg / 16.42 pounds 3 460 Gs	1.12 kg / 2.46 pounds 1117 g / 11.0 N	6.70 kg / 14.78 pounds ~0 Gs
10 mm	4.78 kg / 10.53 pounds 2 771 Gs	0.72 kg / 1.58 pounds 717 g / 7.0 N	4.30 kg / 9.48 pounds ~0 Gs
20 mm	1.54 kg / 3.41 pounds 1 576 Gs	0.23 kg / 0.51 pounds 232 g / 2.3 N	1.39 kg / 3.06 pounds ~0 Gs
50 mm	0.06 kg / 0.13 pounds 312 Gs	0.01 kg / 0.02 pounds 9 g / 0.1 N	0.05 kg / 0.12 pounds ~0 Gs
60 mm	0.03 kg / 0.06 pounds 202 Gs	0.00 kg / 0.01 pounds 4 g / 0.0 N	0.02 kg / 0.05 pounds ~0 Gs
70 mm	0.01 kg / 0.03 pounds 138 Gs	0.00 kg / 0.00 pounds 2 g / 0.0 N	0.01 kg / 0.02 pounds ~0 Gs
80 mm	0.01 kg / 0.01 pounds 97 Gs	0.00 kg / 0.00 pounds 1 g / 0.0 N	0.00 kg / 0.00 pounds ~0 Gs
90 mm	0.00 kg / 0.01 pounds 71 Gs	0.00 kg / 0.00 pounds 0 g / 0.0 N	0.00 kg / 0.00 pounds ~0 Gs
100 mm	0.00 kg / 0.00 pounds 54 Gs	0.00 kg / 0.00 pounds 0 g / 0.0 N	0.00 kg / 0.00 pounds ~0 Gs

Two strong neodymiums attract each other from a wider radius than a neodymium and metal setup. The connection of two magnets generates a stronger field and a wider radius of performance. Designing a strong closure? Use a pair of magnets instead of a neodymium and a striker plate. Exercise caution that when connecting a pair of magnets, the collision energy is massive. The repulsion force is slightly lower than the attraction, but still impressive.
*Field value in repulsion mode drops to ~0 Gs at the midpoint between the magnets (resulting from vector opposition).
Important: Estimates apply to sliding force of dual matching magnets (friction coefficient ~0.15 for Ni-Ni coating).

Table 7: Hazards (electronics) - precautionary measures
MP 25x7.5/4.5x5 / N38

Object / Device	Limit (Gauss) / mT	Safe distance
Pacemaker	5 Gs (0.5 mT)	9.5 cm
Hearing aid	10 Gs (1.0 mT)	7.5 cm
Timepiece	20 Gs (2.0 mT)	6.0 cm
Phone / Smartphone	40 Gs (4.0 mT)	4.5 cm
Car key	50 Gs (5.0 mT)	4.0 cm
Payment card	400 Gs (40.0 mT)	2.0 cm
HDD hard drive	600 Gs (60.0 mT)	1.5 cm

A strong magnetic field poses a serious hazard to electronics as well as medical implants. These magnets generate a flux that destroys function of digital equipment. Notice: the unseen radiation passes through tissues and glass. Special caution must be exercised by people with cochlear implants and insulin pumps. Also at risk are: automatic timepieces, car keys, membranes, and screens. Avoid contact with magnetic cards, HDD media, or sensitive navigation tools.

Table 8: Collisions (kinetic energy) - warning
MP 25x7.5/4.5x5 / N38

Start from (mm)	Speed (km/h)	Energy (J)
10 mm	22.95 km/h (6.38 m/s)	0.36 J
30 mm	36.43 km/h (10.12 m/s)	0.91 J
50 mm	46.96 km/h (13.04 m/s)	1.52 J
100 mm	66.40 km/h (18.44 m/s)	3.03 J

NdFeB products are prone to chipping – a strong collision with metal causes immediate chipping. Watch the impact speed – a magnet released freely becomes dangerous. Impact energy can destroy the magnet or dangerous crushing to fingers. Hold the magnet firmly during mounting so it doesn't slam with momentum against the metal. A collision at high speed ends with a crack of the neodymium. Wear eye protection when handling with powerful specimens.

Table 9: Anti-corrosion coating durability
MP 25x7.5/4.5x5 / 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)

For outdoor applications, an epoxy coating is required; standard nickel is intended for indoor use. Moisture resistance is crucial for installations in bathrooms or outdoors.

Table 10: Construction data (Flux)
MP 25x7.5/4.5x5 / N38

Parameter	Value	SI Unit / Description
Magnetic Flux	9 759 Mx	97.6 µWb
P_c Coefficient	0.25	Low (Flat)

Flux value passing through the pole surface. Key data in coil applications and motors. P_c value defines the working geometry.

Table 11: Hydrostatics and buoyancy
MP 25x7.5/4.5x5 / N38

Environment	Effective steel pull	Effect
Air (land)	7.72 kg	Standard
Water (riverbed)	8.84 kg (+1.12 kg buoyancy gain)	+14.5%

Warning: Remember to wipe the magnet thoroughly after removing it from water and apply a protective layer (e.g., oil) to avoid corrosion.

Water displaces steel, making heavy objects slightly lighter. As a result, your magnet will pull a heavier object from the bottom than if you lifted it in the air.

1. Wall mount (shear)

*Warning: On a vertical surface, the magnet holds just a fraction of its max power.

2. Steel saturation

*Thin steel (e.g. computer case) significantly reduces the holding force.

3. Heat tolerance

*For standard magnets, the safety limit is 80°C.

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

chart generated for the permeance coefficient P_c (Permeance Coefficient) = 0.25

The chart above illustrates the magnetic characteristics of the material within the second quadrant of the hysteresis loop. 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 P_c (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 P_c 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

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: 030194-2026

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Input a figure in just one field to see the conversion for the other fields at once.

MW 8x3 / N38 - cylindrical magnet

0.701 ZŁ brutto / pcs

Product available Ships today (order by 14:00)

MW 25x5 / N38AH - cylindrical magnet

16.68 ZŁ brutto / pcs

Product available Ships today (order by 14:00)

MP 15x7/3.5x5 / N38 - ring magnet

3.44 ZŁ brutto / pcs

Product available Ships today (order by 14:00)

MPL 40x5x3 / N38 - lamellar magnet

6.65 ZŁ brutto / pcs

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. This product with a force of 7.72 kg works great as a cabinet closure, speaker holder, or spacer element in devices.

This is a crucial issue when working with model MP 25x7.5/4.5x5 / N38. Neodymium magnets are sintered ceramics, which means they are hard but breakable and inelastic. One turn too many can destroy the magnet, so do it slowly. It's a good idea to use a flexible washer under the screw head, which will cushion the stresses. Remember: cracking during assembly results from material properties, not a product defect.

These magnets are coated with standard Ni-Cu-Ni plating, which protects them in indoor conditions, but is not sufficient for rain. 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. This product is dedicated for indoor use. For outdoor applications, we recommend choosing magnets in hermetic housing or additional protection with varnish.

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.

This model is characterized by dimensions Ø25x5 mm and a weight of 17.81 g. The key parameter here is the lifting capacity amounting to approximately 7.72 kg (force ~75.69 N). The product has a [NiCuNi] coating and is made of NdFeB material. Inner hole dimension: 7.5/4.5 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 and weaknesses of Nd₂Fe₁₄B magnets.

Benefits

Besides their tremendous pulling force, neodymium magnets offer the following advantages:

They do not lose strength, even during around 10 years – the reduction in lifting capacity is only ~1% (theoretically),
Magnets effectively protect themselves against loss of magnetization caused by foreign field sources,
By covering with a shiny coating of gold, the element gains an modern look,
Magnetic induction on the working layer of the magnet remains extremely intense,
Through (adequate) combination of ingredients, they can achieve high thermal resistance, enabling functioning at temperatures reaching 230°C and above...
Possibility of custom forming as well as adjusting to defined requirements,
Universal use in modern industrial fields – they are commonly used in HDD drives, electric motors, advanced medical instruments, and complex engineering applications.
Thanks to efficiency per cm³, small magnets offer high operating force, occupying minimum space,

Cons

Cons of neodymium magnets and proposals for their use:

At strong impacts they can crack, therefore we recommend placing them in steel cases. A metal housing provides additional protection against damage and increases the magnet's durability.
Neodymium magnets lose their force under the influence of heating. As soon as 80°C is exceeded, many of them start losing their power. Therefore, we recommend our special magnets marked [AH], which maintain stability even at temperatures up to 230°C
When exposed to humidity, magnets start to rust. To use them in conditions outside, it is recommended to use protective magnets, such as magnets in rubber or plastics, which prevent oxidation and corrosion.
Due to limitations in creating nuts and complex forms in magnets, we propose using a housing - magnetic holder.
Possible danger related to microscopic parts of magnets pose a threat, if swallowed, which gains importance in the context of child safety. Furthermore, small components of these products can disrupt the diagnostic process medical in case of swallowing.
With large orders the cost of neodymium magnets is a challenge,

Lifting parameters

Optimal lifting capacity of a neodymium magnet – what contributes to it?

The load parameter shown concerns the maximum value, measured under laboratory conditions, namely:

using a sheet made of mild steel, acting as a circuit closing element
possessing a thickness of min. 10 mm to ensure full flux closure
characterized by lack of roughness
with direct contact (no impurities)
during pulling in a direction vertical to the mounting surface
in neutral thermal conditions

Practical lifting capacity: influencing factors

Bear in mind that the working load will differ influenced by the following factors, in order of importance:

Space between surfaces – every millimeter of distance (caused e.g. by veneer or dirt) diminishes the magnet efficiency, often by half at just 0.5 mm.
Pull-off angle – note that the magnet has greatest strength perpendicularly. Under sliding down, the holding force drops significantly, often to levels of 20-30% of the maximum value.
Substrate thickness – for full efficiency, the steel must be adequately massive. Paper-thin metal restricts the lifting capacity (the magnet "punches through" it).
Material composition – different alloys attracts identically. Alloy additives worsen the interaction with the magnet.
Surface condition – smooth surfaces ensure maximum contact, which increases force. Uneven metal reduce efficiency.
Temperature – temperature increase results in weakening of induction. It is worth remembering the thermal limit for a given model.

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

Warnings

Do not drill into magnets

Fire hazard: Rare earth powder is explosive. Avoid machining magnets without safety gear as this may cause fire.

Threat to electronics

Avoid bringing magnets close to a purse, laptop, or TV. The magnetic field can permanently damage these devices and erase data from cards.

Danger to the youngest

Neodymium magnets are not suitable for play. Eating a few magnets can lead to them pinching intestinal walls, which constitutes a critical condition and necessitates immediate surgery.

Bone fractures

Protect your hands. Two powerful magnets will join immediately with a force of several hundred kilograms, destroying everything in their path. Exercise extreme caution!

Warning for allergy sufferers

Certain individuals experience a hypersensitivity to nickel, which is the standard coating for NdFeB magnets. Frequent touching might lead to an allergic reaction. We strongly advise wear protective gloves.

Magnet fragility

Watch out for shards. Magnets can explode upon violent connection, launching shards into the air. We recommend safety glasses.

Do not overheat magnets

Regular neodymium magnets (grade N) lose magnetization when the temperature exceeds 80°C. Damage is permanent.

Keep away from electronics

A strong magnetic field disrupts the functioning of magnetometers in phones and navigation systems. Keep magnets near a device to avoid damaging the sensors.

Health Danger

Health Alert: Strong magnets can deactivate heart devices and defibrillators. Stay away if you have electronic implants.

Powerful field

Before starting, check safety instructions. Sudden snapping can break the magnet or injure your hand. Be predictive.

Security! Looking for details? Check our post: Why are neodymium magnets dangerous?

MP 25x7.5/4.5x5 / N38 - ring magnet

Technical of the product - MP 25x7.5/4.5x5 / N38 - ring magnet

Magnetic properties of material N38

Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C

Technical analysis of the product - report

Table 1: Static force (force vs distance) - power drop MP 25x7.5/4.5x5 / N38

Table 2: Shear force (wall) MP 25x7.5/4.5x5 / N38

Table 3: Wall mounting (sliding) - vertical pull MP 25x7.5/4.5x5 / N38

Table 4: Steel thickness (substrate influence) - power losses MP 25x7.5/4.5x5 / N38

Table 5: Thermal resistance (stability) - thermal limit MP 25x7.5/4.5x5 / N38

Table 6: Magnet-Magnet interaction (attraction) - forces in the system MP 25x7.5/4.5x5 / N38

Table 7: Hazards (electronics) - precautionary measures MP 25x7.5/4.5x5 / N38

Table 8: Collisions (kinetic energy) - warning MP 25x7.5/4.5x5 / N38

Table 9: Anti-corrosion coating durability MP 25x7.5/4.5x5 / N38

Table 10: Construction data (Flux) MP 25x7.5/4.5x5 / N38

Table 11: Hydrostatics and buoyancy MP 25x7.5/4.5x5 / N38

1. Wall mount (shear)

2. Steel saturation

3. Heat tolerance

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

Chemical composition

Sustainability

Force (pull)

Magnetic Field

See also products

MW 8x3 / N38 - cylindrical magnet

MW 25x5 / N38AH - cylindrical magnet

MP 15x7/3.5x5 / N38 - ring magnet

MPL 40x5x3 / N38 - lamellar magnet

Strengths and weaknesses of Nd2Fe14B magnets.

Benefits

Cons

Lifting parameters

Optimal lifting capacity of a neodymium magnet – what contributes to it?

Practical lifting capacity: influencing factors

Warnings

Do not drill into magnets

Threat to electronics

Danger to the youngest

Bone fractures

Warning for allergy sufferers

Magnet fragility

Do not overheat magnets

Keep away from electronics

Health Danger

Powerful field

Physical properties of sintered neodymium magnets Nd₂Fe₁₄B at 20°C

Table 1: Static force (force vs distance) - power drop
MP 25x7.5/4.5x5 / N38

Table 2: Shear force (wall)
MP 25x7.5/4.5x5 / N38

Table 3: Wall mounting (sliding) - vertical pull
MP 25x7.5/4.5x5 / N38

Table 4: Steel thickness (substrate influence) - power losses
MP 25x7.5/4.5x5 / N38

Table 5: Thermal resistance (stability) - thermal limit
MP 25x7.5/4.5x5 / N38

Table 6: Magnet-Magnet interaction (attraction) - forces in the system
MP 25x7.5/4.5x5 / N38

Table 7: Hazards (electronics) - precautionary measures
MP 25x7.5/4.5x5 / N38

Table 8: Collisions (kinetic energy) - warning
MP 25x7.5/4.5x5 / N38

Table 9: Anti-corrosion coating durability
MP 25x7.5/4.5x5 / N38

Table 10: Construction data (Flux)
MP 25x7.5/4.5x5 / N38

Table 11: Hydrostatics and buoyancy
MP 25x7.5/4.5x5 / N38

Strengths and weaknesses of Nd₂Fe₁₄B magnets.