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MW 15x4 / N38 - cylindrical magnet

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

cylindrical magnet

Catalog no 010030

GTIN/EAN: 5906301810292

5.00

Diameter Ø

15 mm [±0,1 mm]

Height

4 mm [±0,1 mm]

Weight

5.3 g

Magnetization Direction

↑ axial

Load capacity

4.22 kg / 41.38 N

Magnetic Induction

291.60 mT / 2916 Gs

Coating

[NiCuNi] Nickel

1.968 ZŁ with VAT / pcs + price for transport

1.600 ZŁ net + 23% VAT / pcs

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MW 15x4 / N38 - cylindrical magnet

Specification / characteristics MW 15x4 / N38 - cylindrical magnet

properties

properties	values
Cat. no.	010030
GTIN/EAN	5906301810292
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 Ø	15 mm [±0,1 mm]
Height	4 mm [±0,1 mm]
Weight	5.3 g
Magnetization Direction	↑ axial
Load capacity ~ ?	4.22 kg / 41.38 N
Magnetic Induction ~ ?	291.60 mT / 2916 Gs
Coating	[NiCuNi] Nickel
Manufacturing Tolerance	±0.1 mm

Magnetic properties of material N38

Specification / characteristics MW 15x4 / N38 - cylindrical 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

Physical analysis of the product - report

These information are the direct effect of a engineering simulation. Results rely on algorithms for the class Nd₂Fe₁₄B. Operational parameters may deviate from the simulation results. Treat these data as a supplementary guide for designers.

Table 1: Static force (force vs distance) - interaction chart
MW 15x4 / N38

Distance (mm)	Induction (Gauss) / mT	Pull Force (kg)	Risk Status
0 mm	2915 Gs 291.5 mT	4.22 kg / 4220.0 g 41.4 N	medium risk
1 mm	2620 Gs 262.0 mT	3.41 kg / 3408.2 g 33.4 N	medium risk
2 mm	2276 Gs 227.6 mT	2.57 kg / 2571.6 g 25.2 N	medium risk
3 mm	1928 Gs 192.8 mT	1.85 kg / 1845.5 g 18.1 N	weak grip
5 mm	1324 Gs 132.4 mT	0.87 kg / 870.3 g 8.5 N	weak grip
10 mm	505 Gs 50.5 mT	0.13 kg / 126.7 g 1.2 N	weak grip
15 mm	222 Gs 22.2 mT	0.02 kg / 24.4 g 0.2 N	weak grip
20 mm	113 Gs 11.3 mT	0.01 kg / 6.3 g 0.1 N	weak grip
30 mm	40 Gs 4.0 mT	0.00 kg / 0.8 g 0.0 N	weak grip
50 mm	10 Gs 1.0 mT	0.00 kg / 0.0 g 0.0 N	weak grip

Grip strength decreases drastically with every subsequent millimeter of distance. Keep in mind that even the smallest gap (e.g., dirt, paint, rust) noticeably reduces the pull force. Magnetic products work strongest in perfect adhesion; air break weakens the power. Notice how flashily the load capacity plummet, when the product does not adhere flatly to the steel surface. When planning the assembly, discard additional spacers.

Table 2: Slippage Load (Vertical Surface)
MW 15x4 / N38

Distance (mm)	Friction coefficient	Pull Force (kg)
0 mm	Stal (~0.2)	0.84 kg / 844.0 g 8.3 N
1 mm	Stal (~0.2)	0.68 kg / 682.0 g 6.7 N
2 mm	Stal (~0.2)	0.51 kg / 514.0 g 5.0 N
3 mm	Stal (~0.2)	0.37 kg / 370.0 g 3.6 N
5 mm	Stal (~0.2)	0.17 kg / 174.0 g 1.7 N
10 mm	Stal (~0.2)	0.03 kg / 26.0 g 0.3 N
15 mm	Stal (~0.2)	0.00 kg / 4.0 g 0.0 N
20 mm	Stal (~0.2)	0.00 kg / 2.0 g 0.0 N
30 mm	Stal (~0.2)	0.00 kg / 0.0 g 0.0 N
50 mm	Stal (~0.2)	0.00 kg / 0.0 g 0.0 N

The following data defines the theoretical holding capacity necessary to start the sliding of the magnet down on a vertical metal surface (assuming standard friction). This parameter is a function of the separation distance between the magnet and the metal.

Table 3: Wall mounting (shearing) - behavior on slippery surfaces
MW 15x4 / N38

Surface type	Friction coefficient / % Mocy	Max load (kg)
Raw steel	µ = 0.3 30% Nominalnej Siły	1.27 kg / 1266.0 g 12.4 N
Painted steel (standard)	µ = 0.2 20% Nominalnej Siły	0.84 kg / 844.0 g 8.3 N
Oily/slippery steel	µ = 0.1 10% Nominalnej Siły	0.42 kg / 422.0 g 4.1 N
Magnet with anti-slip rubber	µ = 0.5 50% Nominalnej Siły	2.11 kg / 2110.0 g 20.7 N

When hanging a element on a upright surface (e.g., a fridge), it you can count on barely approx. 1/5 of its nominal power. Gravitational force and a low friction coefficient influence the fact that magnets slide down faster than they pop off the substrate. Want to create a wall mount? Consider that the sliding force is significantly lower than the perpendicular breakaway force. On a painted metal, the element will slip down under a noticeably lighter load. Utilizing a rubberized coating can drastically improve the result.

Table 4: Steel thickness (substrate influence) - sheet metal selection
MW 15x4 / N38

Steel thickness (mm)	% power	Real pull force (kg)
0.5 mm	10%	0.42 kg / 422.0 g 4.1 N
1 mm	25%	1.06 kg / 1055.0 g 10.3 N
2 mm	50%	2.11 kg / 2110.0 g 20.7 N
5 mm	100%	4.22 kg / 4220.0 g 41.4 N
10 mm	100%	4.22 kg / 4220.0 g 41.4 N

A too thin steel is incapable of conduct the full magnetic flux, which weakens actual performance of the magnet. If you mount a strong magnet to a weak sheet, the flux will penetrate right through and the pull force will drop sharply. To achieve 100% of this neodymium's power, you require a sufficiently solid backing of metal. The saturation effect means that on delicate walls (e.g., thin profiles), the holder holds weaker. We recommend selecting the steel cross-section from these parameters.

Table 5: Working in heat (stability) - thermal limit
MW 15x4 / N38

Ambient temp. (°C)	Power loss	Remaining pull	Status
20 °C	0.0%	4.22 kg / 4220.0 g 41.4 N	OK
40 °C	-2.2%	4.13 kg / 4127.2 g 40.5 N	OK
60 °C	-4.4%	4.03 kg / 4034.3 g 39.6 N
80 °C	-6.6%	3.94 kg / 3941.5 g 38.7 N
100 °C	-28.8%	3.00 kg / 3004.6 g 29.5 N

Ordinary NdFeB products irreversibly lose strength after exceeding the maximum temperature. Avoid high temperatures – heat can permanently damage this product. With increasing heat, the magnet's force briefly lowers. Avoid using this product in hot environments exceeding its working range. Ignoring the limit will cause permanent loss of magnetic properties.

*Technical advisory: Temperature resistance depends not only on the material grade, and the Permeance Coefficient Pc. Low-profile magnets (low permeance coefficient) risk losing magnetic properties under lower heat stress than long magnets. The danger warning in the table indicates permanent field degradation for this specific geometry.

Table 6: Two magnets (repulsion) - forces in the system
MW 15x4 / N38

Gap (mm)	Attraction (kg) (N-S)	Repulsion (kg) (N-N)
0 mm	9.26 kg / 9258 g 90.8 N 4 518 Gs	N/A
1 mm	8.40 kg / 8404 g 82.4 N 5 555 Gs	7.56 kg / 7564 g 74.2 N ~0 Gs
2 mm	7.48 kg / 7477 g 73.3 N 5 239 Gs	6.73 kg / 6729 g 66.0 N ~0 Gs
3 mm	6.54 kg / 6542 g 64.2 N 4 901 Gs	5.89 kg / 5888 g 57.8 N ~0 Gs
5 mm	4.80 kg / 4804 g 47.1 N 4 200 Gs	4.32 kg / 4324 g 42.4 N ~0 Gs
10 mm	1.91 kg / 1909 g 18.7 N 2 648 Gs	1.72 kg / 1718 g 16.9 N ~0 Gs
20 mm	0.28 kg / 278 g 2.7 N 1 010 Gs	0.25 kg / 250 g 2.5 N ~0 Gs
50 mm	0.00 kg / 4 g 0.0 N 128 Gs	0.00 kg / 0 g 0.0 N ~0 Gs

Two strong neodymiums interact from a wider radius than a magnet and sheet combination. The connection of magnet-to-magnet creates a more powerful interaction and a further horizon of performance. Want to build a strong closure? Apply two magnets instead of a neodymium and a steel. Remember that when bringing together two magnets, the collision energy is massive. The repulsion force is a bit weaker than the attraction, but still significant.
*Field value in repulsion mode is approximately ~0 Gs at the geometric center between the magnets (caused by magnetic field nullification).

Table 7: Safety (HSE) (electronics) - precautionary measures
MW 15x4 / N38

Object / Device	Limit (Gauss) / mT	Safe distance
Pacemaker	5 Gs (0.5 mT)	6.5 cm
Hearing aid	10 Gs (1.0 mT)	5.0 cm
Mechanical watch	20 Gs (2.0 mT)	4.0 cm
Phone / Smartphone	40 Gs (4.0 mT)	3.0 cm
Car key	50 Gs (5.0 mT)	3.0 cm
Payment card	400 Gs (40.0 mT)	1.5 cm
HDD hard drive	600 Gs (60.0 mT)	1.0 cm

Powerful magnet radiation poses a real danger to electronic devices and medical implants. These neodymiums produce a flux that destroys function of digital equipment. Remember: the invisible magnetic field acts through matter and glass. Exceptional care must be exercised by people with hearing aids and insulin pumps. Influence will be felt by: automatic timepieces, car keys, speakers, and screens. Do not place the magnet near cards, hard drives, or precise measuring instruments.

Table 8: Dynamics (cracking risk) - warning
MW 15x4 / N38

Start from (mm)	Speed (km/h)	Energy (J)
10 mm	28.99 km/h (8.05 m/s)	0.17 J
30 mm	49.30 km/h (13.69 m/s)	0.50 J
50 mm	63.63 km/h (17.68 m/s)	0.83 J
100 mm	89.99 km/h (25.00 m/s)	1.66 J

Magnetic elements are prone to chipping – a violent impact against metal risks their cracking. Pay attention to connection velocity – a magnet released freely turns into a projectile. Striking energy can cause material chips or painful pinches to fingers. Hold the magnet firmly during bringing near metal so it doesn't slam with momentum against the metal. A contact at a velocity of dozens of km/h ends with a crack of the neodymium. Wear eye protection when playing with large magnets.

Table 9: Surface protection spec
MW 15x4 / 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)

Neodymium magnets are highly susceptible to corrosion without proper protection. Improper coating selection is the most common cause of magnet failure over time.

Table 10: Construction Data (Flux)
MW 15x4 / N38

Parameter	Value	SI Unit / Description
Magnetic Flux	5 659 Mx	56.6 µWb
P_c Coefficient	0.37	Low (Flat)

Flux value passing through the magnet pole. Essential parameter in coil applications and motors. P_c value defines the magnet's operating point.

Table 11: Physics of underwater searching
MW 15x4 / N38

Environment	Effective steel pull	Effect
Air (land)	4.22 kg	Standard
Water (riverbed)	4.83 kg (+0.61 kg Buoyancy gain)	+14.5%

Warning: Standard nickel requires drying after every contact with moisture; lack of maintenance will lead to rust spots.

In water, the magnet feels stronger thanks to Archimedes' principle. 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)

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

2. Plate thickness effect

*Thin steel (e.g. 0.5mm PC case) significantly limits the holding force.

3. Temperature resistance

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

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

chart generated for the permeance coefficient P_c (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 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%

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: 010030-2025

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MPL 30x15x2 / N38 - lamellar magnet

3.89 ZŁ brutto / pcs

The presented product is an exceptionally strong cylindrical magnet, made from modern NdFeB material, which, at dimensions of Ø15x4 mm, guarantees the highest energy density. This specific item is characterized by high dimensional repeatability and professional build quality, making it a perfect solution for the most demanding engineers and designers. As a magnetic rod with significant force (approx. 4.22 kg), this product is in stock from our warehouse in Poland, ensuring quick order fulfillment. Moreover, its Ni-Cu-Ni coating secures it against corrosion in typical operating conditions, ensuring an aesthetic appearance and durability for years.

This model is created for building electric motors, advanced Hall effect sensors, and efficient magnetic separators, where maximum induction on a small surface counts. Thanks to the high power of 41.38 N with a weight of only 5.3 g, this cylindrical magnet is indispensable in electronics and wherever low weight is crucial.

Since our magnets have a very precise dimensions, the recommended way is to glue them into holes with a slightly larger diameter (e.g., 15.1 mm) using epoxy glues. To ensure long-term durability in industry, specialized industrial adhesives are used, which are safe for nickel and fill the gap, guaranteeing high repeatability of the connection.

Grade N38 is the most frequently chosen standard for professional neodymium magnets, offering a great economic balance and high resistance to demagnetization. If you need even stronger magnets in the same volume (Ø15x4), contact us regarding higher grades (e.g., N50, N52), however, N38 is the standard available off-the-shelf in our store.

This model is characterized by dimensions Ø15x4 mm, which, at a weight of 5.3 g, makes it an element with high magnetic energy density. The value of 41.38 N means that the magnet is capable of holding a weight many times exceeding its own mass of 5.3 g. The product has a [NiCuNi] coating, which protects the surface against oxidation, giving it an aesthetic, silvery shine.

This cylinder is magnetized axially (along the height of 4 mm), which means that the N and S poles are located on the flat, circular surfaces. Such an arrangement is standard when connecting magnets in stacks (e.g., in filters) or when mounting in sockets at the bottom of a hole. On request, we can also produce versions magnetized diametrically if your project requires it.

Pros and cons of neodymium magnets.

Strengths

Besides their immense strength, neodymium magnets offer the following advantages:

They virtually do not lose power, because even after 10 years the performance loss is only ~1% (according to literature),
Neodymium magnets are characterized by extremely resistant to loss of magnetic properties caused by external interference,
A magnet with a shiny silver surface is more attractive,
Magnetic induction on the working layer of the magnet is extremely intense,
Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
Possibility of accurate modeling and adjusting to individual applications,
Universal use in future technologies – they are used in magnetic memories, brushless drives, diagnostic systems, and complex engineering applications.
Thanks to concentrated force, small magnets offer high operating force, with minimal size,

Weaknesses

Disadvantages of NdFeB magnets:

They are fragile upon heavy impacts. To avoid cracks, it is worth securing magnets using a steel holder. Such protection not only protects 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
Magnets exposed to a humid environment can corrode. Therefore when using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
Limited possibility of creating nuts in the magnet and complex shapes - preferred is a housing - magnetic holder.
Possible danger resulting from small fragments of magnets can be dangerous, in case of ingestion, which is particularly important in the context of child health protection. It is also worth noting that tiny parts of these devices are able to disrupt the diagnostic process medical in case of swallowing.
With budget limitations the cost of neodymium magnets can be a barrier,

Pull force analysis

Detachment force of the magnet in optimal conditions – what contributes to it?

The declared magnet strength represents the maximum value, recorded under laboratory conditions, meaning:

on a plate made of mild steel, effectively closing the magnetic flux
with a thickness minimum 10 mm
with an ideally smooth touching surface
under conditions of gap-free contact (surface-to-surface)
under vertical force vector (90-degree angle)
at conditions approx. 20°C

Practical aspects of lifting capacity – factors

Holding efficiency is influenced by specific conditions, such as (from most important):

Space between magnet and steel – every millimeter of distance (caused e.g. by varnish or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
Load vector – highest force is obtained only during perpendicular pulling. The shear force of the magnet along the surface is usually many times smaller (approx. 1/5 of the lifting capacity).
Plate thickness – too thin steel does not accept the full field, causing part of the power to be wasted to the other side.
Plate material – mild steel attracts best. Higher carbon content decrease magnetic properties and lifting capacity.
Surface condition – smooth surfaces guarantee perfect abutment, which increases field saturation. Uneven metal weaken the grip.
Thermal factor – hot environment weakens pulling force. Exceeding the limit temperature can permanently demagnetize the magnet.

Lifting capacity was determined by applying a polished steel plate 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’s surface and the plate reduces the lifting capacity.

Safe handling of neodymium magnets

Eye protection

NdFeB magnets are ceramic materials, meaning they are very brittle. Collision of two magnets will cause them breaking into small pieces.

GPS Danger

Remember: neodymium magnets generate a field that confuses sensitive sensors. Maintain a separation from your mobile, tablet, and GPS.

Fire risk

Drilling and cutting of neodymium magnets poses a fire risk. Neodymium dust reacts violently with oxygen and is difficult to extinguish.

Choking Hazard

Strictly store magnets away from children. Ingestion danger is significant, and the effects of magnets clamping inside the body are life-threatening.

Warning for heart patients

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

Avoid contact if allergic

Some people experience a contact allergy to Ni, which is the typical protective layer for neodymium magnets. Frequent touching might lead to skin redness. We strongly advise use protective gloves.

Do not overheat magnets

Do not overheat. NdFeB magnets are susceptible to temperature. If you require operation above 80°C, ask us about HT versions (H, SH, UH).

Serious injuries

Watch your fingers. Two large magnets will join instantly with a force of several hundred kilograms, crushing everything in their path. Be careful!

Handling guide

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

Data carriers

Avoid bringing magnets near a wallet, laptop, or screen. The magnetic field can irreversibly ruin these devices and wipe information from cards.

Attention! Details about risks in the article: Safety of working with magnets.

MW 15x4 / N38 - cylindrical magnet

Looking for a better price?

MW 15x4 / N38 - cylindrical magnet

Magnetic properties of material N38

Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C

Physical analysis of the product - report

1. Wall mount (shear)

2. Plate thickness effect

3. Temperature resistance

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

Chemical composition

Environmental data

Magnet Pull Force

Magnetic Induction

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MPL 30x15x2 / N38 - lamellar magnet

Pros and cons of neodymium magnets.

Strengths

Weaknesses

Pull force analysis

Detachment force of the magnet in optimal conditions – what contributes to it?

Practical aspects of lifting capacity – factors

Eye protection

GPS Danger

Fire risk

Choking Hazard

Warning for heart patients

Avoid contact if allergic

Do not overheat magnets

Serious injuries

Handling guide

Data carriers

Physical properties of sintered neodymium magnets Nd₂Fe₁₄B at 20°C