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MPL 20x8x4 / N38 - lamellar 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

lamellar magnet

Catalog no 020133

GTIN/EAN: 5906301811398

5.00

length

20 mm [±0,1 mm]

Width

8 mm [±0,1 mm]

Height

4 mm [±0,1 mm]

Weight

4.8 g

Magnetization Direction

↑ axial

Load capacity

4.79 kg / 46.98 N

Magnetic Induction

336.99 mT / 3370 Gs

Coating

[NiCuNi] Nickel

3.67 ZŁ with VAT / pcs + price for transport

2.98 ZŁ net + 23% VAT / pcs

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MPL 20x8x4 / N38 - lamellar magnet

Specification / characteristics MPL 20x8x4 / N38 - lamellar magnet

properties

properties	values
Cat. no.	020133
GTIN/EAN	5906301811398
Production/Distribution	Dhit sp. z o.o. ul. Zielona 14 05-850 Ożarów Mazowiecki PL
Country of origin	Poland / China / Germany
Customs code	85059029
length	20 mm [±0,1 mm]
Width	8 mm [±0,1 mm]
Height	4 mm [±0,1 mm]
Weight	4.8 g
Magnetization Direction	↑ axial
Load capacity ~ ?	4.79 kg / 46.98 N
Magnetic Induction ~ ?	336.99 mT / 3370 Gs
Coating	[NiCuNi] Nickel
Manufacturing Tolerance	±0.1 mm

Magnetic properties of material N38

Specification / characteristics MPL 20x8x4 / N38 - lamellar 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 - data

Presented data are the direct effect of a engineering calculation. Values rely on algorithms for the class Nd₂Fe₁₄B. Operational conditions might slightly differ from theoretical values. Please consider these calculations as a supplementary guide for designers.

Table 1: Static force (pull vs gap) - power drop
MPL 20x8x4 / N38

Distance (mm)	Induction (Gauss) / mT	Pull Force (kg)	Risk Status
0 mm	3368 Gs 336.8 mT	4.79 kg / 4790.0 g 47.0 N	warning
1 mm	2818 Gs 281.8 mT	3.35 kg / 3352.3 g 32.9 N	warning
2 mm	2266 Gs 226.6 mT	2.17 kg / 2167.6 g 21.3 N	warning
3 mm	1794 Gs 179.4 mT	1.36 kg / 1358.6 g 13.3 N	low risk
5 mm	1130 Gs 113.0 mT	0.54 kg / 538.9 g 5.3 N	low risk
10 mm	416 Gs 41.6 mT	0.07 kg / 73.0 g 0.7 N	low risk
15 mm	187 Gs 18.7 mT	0.01 kg / 14.7 g 0.1 N	low risk
20 mm	97 Gs 9.7 mT	0.00 kg / 4.0 g 0.0 N	low risk
30 mm	35 Gs 3.5 mT	0.00 kg / 0.5 g 0.0 N	low risk
50 mm	9 Gs 0.9 mT	0.00 kg / 0.0 g 0.0 N	low risk

Magnetic force decreases sharply with every mm of gap. Keep in mind that every additional insulation layer (e.g., dirt, varnish, veneer) strongly diminishes the holding power. Magnets hold most effectively during direct contact; gap drastically cuts the power. Analyze how quickly the parameters drop, when the product does not touch flatly to the steel surface. When calculating the assembly, discard unnecessary gaps.

Table 2: Shear load (vertical surface)
MPL 20x8x4 / N38

Distance (mm)	Friction coefficient	Pull Force (kg)
0 mm	Stal (~0.2)	0.96 kg / 958.0 g 9.4 N
1 mm	Stal (~0.2)	0.67 kg / 670.0 g 6.6 N
2 mm	Stal (~0.2)	0.43 kg / 434.0 g 4.3 N
3 mm	Stal (~0.2)	0.27 kg / 272.0 g 2.7 N
5 mm	Stal (~0.2)	0.11 kg / 108.0 g 1.1 N
10 mm	Stal (~0.2)	0.01 kg / 14.0 g 0.1 N
15 mm	Stal (~0.2)	0.00 kg / 2.0 g 0.0 N
20 mm	Stal (~0.2)	0.00 kg / 0.0 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 table below shows the theoretical holding capacity needed to cause the slippage of the magnet down against a upright steel wall (considering standard friction). This parameter is relative to the distance between the magnet and the metal.

Table 3: Wall mounting (sliding) - vertical pull
MPL 20x8x4 / N38

Surface type	Friction coefficient / % Mocy	Max load (kg)
Raw steel	µ = 0.3 30% Nominalnej Siły	1.44 kg / 1437.0 g 14.1 N
Painted steel (standard)	µ = 0.2 20% Nominalnej Siły	0.96 kg / 958.0 g 9.4 N
Oily/slippery steel	µ = 0.1 10% Nominalnej Siły	0.48 kg / 479.0 g 4.7 N
Magnet with anti-slip rubber	µ = 0.5 50% Nominalnej Siły	2.40 kg / 2395.0 g 23.5 N

When placing a element on a upright plane (e.g., a board), it you can count on just approx. 20%-30% of its maximum pull force. Gravity and a low friction coefficient cause that products slide down faster than they detach. Designing a hanger? Remember that the shear force is noticeably lower than the perpendicular breakaway force. On a slippery surface, the element will give way down under a noticeably lighter load. Application of an anti-slip layer can drastically raise the stability.

Table 4: Material efficiency (substrate influence) - power losses
MPL 20x8x4 / N38

Steel thickness (mm)	% power	Real pull force (kg)
0.5 mm	10%	0.48 kg / 479.0 g 4.7 N
1 mm	25%	1.20 kg / 1197.5 g 11.7 N
2 mm	50%	2.40 kg / 2395.0 g 23.5 N
5 mm	100%	4.79 kg / 4790.0 g 47.0 N
10 mm	100%	4.79 kg / 4790.0 g 47.0 N

A thin metal plate is incapable of focus the entire magnetic field, which wastes potential of the magnet. Should you attach a powerful product to a thin surface, the magnetism will penetrate right through and the attraction force will be weaker. To achieve full efficiency of this magnet's potential, you need a suitably thick piece of steel. The saturation effect means that on delicate walls (e.g., thin profiles), the magnet shows lower pull force. We recommend selecting the steel cross-section from these parameters.

Table 5: Working in heat (stability) - resistance threshold
MPL 20x8x4 / N38

Ambient temp. (°C)	Power loss	Remaining pull	Status
20 °C	0.0%	4.79 kg / 4790.0 g 47.0 N	OK
40 °C	-2.2%	4.68 kg / 4684.6 g 46.0 N	OK
60 °C	-4.4%	4.58 kg / 4579.2 g 44.9 N
80 °C	-6.6%	4.47 kg / 4473.9 g 43.9 N
100 °C	-28.8%	3.41 kg / 3410.5 g 33.5 N

Classic neodymiums change their properties power after exceeding the maximum temperature. Avoid high temperatures – excessive heat can irreversibly demagnetize this product. With every degree above norm, the magnet's power briefly decreases. Refrain from using this product in hot environments higher than its operating temperature limit. Too high temperature will lead to irreversible degradation of magnetic properties.

*Engineering note: Thermal stability depends not only on the material grade, as well as the dimension ratios. Flat magnets (pancake types) risk losing magnetic properties under lower heat stress compared to rod magnets. Warning indicator in the table indicates a risk of irreversible loss for this particular item.

Table 6: Magnet-Magnet interaction (repulsion) - field collision
MPL 20x8x4 / N38

Gap (mm)	Attraction (kg) (N-S)	Repulsion (kg) (N-N)
0 mm	11.19 kg / 11189 g 109.8 N 4 784 Gs	N/A
1 mm	9.49 kg / 9494 g 93.1 N 6 205 Gs	8.54 kg / 8544 g 83.8 N ~0 Gs
2 mm	7.83 kg / 7830 g 76.8 N 5 635 Gs	7.05 kg / 7047 g 69.1 N ~0 Gs
3 mm	6.34 kg / 6337 g 62.2 N 5 069 Gs	5.70 kg / 5703 g 55.9 N ~0 Gs
5 mm	4.02 kg / 4015 g 39.4 N 4 035 Gs	3.61 kg / 3614 g 35.4 N ~0 Gs
10 mm	1.26 kg / 1259 g 12.3 N 2 259 Gs	1.13 kg / 1133 g 11.1 N ~0 Gs
20 mm	0.17 kg / 171 g 1.7 N 832 Gs	0.15 kg / 154 g 1.5 N ~0 Gs
50 mm	0.00 kg / 3 g 0.0 N 112 Gs	0.00 kg / 0 g 0.0 N ~0 Gs

Two magnetic products attract each other from a much further distance than a magnet and sheet combination. The setup of magnet-to-magnet produces a massive flux and a larger range of operation. Planning to create a powerful holder? Apply two magnets instead of one magnet and a steel. Remember that when bringing together two magnets, the pinch force is massive. The repulsion force is slightly lower than the attraction, but still significant.
*The magnetic induction in repulsion mode drops to ~0 Gs in the exact middle of the gap (due to field cancellation).

Table 7: Safety (HSE) (implants) - warnings
MPL 20x8x4 / 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
Timepiece	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 electronics as well as pacemakers. These neodymiums generate a flux that prevents correct functioning of sensitive medical devices. Notice: the invisible magnetic field passes through tissues and glass. Special caution must be taken by people with cochlear implants and insulin pumps. Also at risk are: mechanical watches, remotes, membranes, and screens. Do not bring the product near payment cards, hard drives, or sensitive navigation tools.

Table 8: Impact energy (cracking risk) - warning
MPL 20x8x4 / N38

Start from (mm)	Speed (km/h)	Energy (J)
10 mm	32.16 km/h (8.93 m/s)	0.19 J
30 mm	55.18 km/h (15.33 m/s)	0.56 J
50 mm	71.24 km/h (19.79 m/s)	0.94 J
100 mm	100.75 km/h (27.99 m/s)	1.88 J

Magnetic elements are delicate – a strong collision with metal risks their cracking. Control the attraction moment – a neodymium left loose speeds with massive force. Kinetic force can destroy the magnet or injury to fingers. Always hold the magnet during mounting so it doesn't hit violently against the metal. A contact at a velocity of dozens of km/h means shattering of the neodymium. Wear eye protection when working with large magnets.

Table 9: Surface protection spec
MPL 20x8x4 / 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. The silver nickel coating also serves an aesthetic function but is not fully waterproof.

Table 10: Electrical data (Flux)
MPL 20x8x4 / N38

Parameter	Value	SI Unit / Description
Magnetic Flux	5 277 Mx	52.8 µWb
P_c Coefficient	0.38	Low (Flat)

Flux value emitted by the pole surface. Essential parameter when building generators and motors. P_c value defines the magnet's operating point.

Table 11: Physics of underwater searching
MPL 20x8x4 / N38

Environment	Effective steel pull	Effect
Air (land)	4.79 kg	Standard
Water (riverbed)	5.48 kg (+0.69 kg Buoyancy gain)	+14.5%

Corrosion warning: This magnet has a standard nickel coating. After use in water, it must be dried and maintained immediately, otherwise it will rust!

Contrary to myths, water does not block the magnetic field. 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 wall, the magnet retains merely approx. 20-30% of its max power.

2. Efficiency vs thickness

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

3. Power loss vs temp

*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) = 0.38

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.

Technical and environmental data

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: 020133-2025

Quick Unit Converter

Force (pull)

Force (N)

Force in lbs

Magnetic Induction

Tesla (T)

Type a value into any field, and the rest change on the fly.

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Model MPL 20x8x4 / N38 features a low profile and industrial pulling force, making it an ideal solution for building separators and machines. This rectangular block with a force of 46.98 N is ready for shipment in 24h, allowing for rapid realization of your project. The durable anti-corrosion layer ensures a long lifespan in a dry environment, protecting the core from oxidation.

Separating strong flat magnets requires a technique based on sliding (moving one relative to the other), rather than forceful pulling apart. Watch your fingers! Magnets with a force of 4.79 kg can pinch very hard and cause hematomas. Never use metal tools for prying, as the brittle NdFeB material may chip and damage your eyes.

They constitute a key element in the production of wind generators and material handling systems. They work great as invisible mounts under tiles, wood, or glass. Customers often choose this model for workshop organization on strips and for advanced DIY and modeling projects, where precision and power count.

Cyanoacrylate glues (super glue type) are good only for small magnets; for larger plates, we recommend resins. Double-sided tape cushions vibrations, which is an advantage when mounting in moving elements. Avoid chemically aggressive glues or hot glue, which can demagnetize neodymium (above 80°C).

The magnetic axis runs through the shortest dimension, which is typical for gripper magnets. In practice, this means that this magnet has the greatest attraction force on its main planes (20x8 mm), which is ideal for flat mounting. Such a pole arrangement ensures maximum holding capacity when pressing against the sheet, creating a closed magnetic circuit.

The presented product is a neodymium magnet with precisely defined parameters: 20 mm (length), 8 mm (width), and 4 mm (thickness). The key parameter here is the holding force amounting to approximately 4.79 kg (force ~46.98 N), which, with such a compact shape, proves the high grade of the material. The product meets the standards for N38 grade magnets.

Advantages and disadvantages of Nd₂Fe₁₄B magnets.

Pros

Besides their durability, neodymium magnets are valued for these benefits:

They retain full power for around ten years – the loss is just ~1% (based on simulations),
They are extremely resistant to demagnetization induced by external field influence,
By using a shiny layer of nickel, the element gains an professional look,
The surface of neodymium magnets generates a strong magnetic field – this is a distinguishing feature,
Due to their durability and thermal resistance, neodymium magnets are capable of operate (depending on the shape) even at high temperatures reaching 230°C or more...
Thanks to the option of flexible forming and adaptation to specialized solutions, NdFeB magnets can be modeled in a broad palette of forms and dimensions, which makes them more universal,
Fundamental importance in innovative solutions – they are commonly used in hard drives, electric drive systems, medical equipment, and industrial machines.
Compactness – despite small sizes they generate large force, making them ideal for precision applications

Cons

Cons of neodymium magnets: application proposals

At very strong impacts they can break, therefore we advise placing them in steel cases. A metal housing provides additional protection against damage, as well as increases the magnet's durability.
When exposed to high temperature, neodymium magnets suffer a drop in force. 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 oxidize in a humid environment - during use outdoors we advise using waterproof magnets e.g. in rubber, plastic
Limited possibility of creating nuts in the magnet and complex shapes - preferred is a housing - mounting mechanism.
Possible danger to health – tiny shards of magnets can be dangerous, if swallowed, which is particularly important in the aspect of protecting the youngest. Additionally, tiny parts of these magnets can disrupt the diagnostic process medical when they are in the body.
Higher cost of purchase is one of the disadvantages compared to ceramic magnets, especially in budget applications

Lifting parameters

Maximum magnetic pulling force – what it depends on?

Breakaway force was defined for the most favorable conditions, taking into account:

on a block made of mild steel, optimally conducting the magnetic field
with a thickness no less than 10 mm
characterized by lack of roughness
without any insulating layer between the magnet and steel
under vertical force vector (90-degree angle)
at room temperature

Practical lifting capacity: influencing factors

In real-world applications, the real power results from a number of factors, listed from most significant:

Space between surfaces – every millimeter of distance (caused e.g. by veneer or dirt) significantly weakens the pulling force, often by half at just 0.5 mm.
Loading method – declared lifting capacity refers to pulling vertically. When applying parallel force, the magnet holds much less (often approx. 20-30% of maximum force).
Steel thickness – insufficiently thick plate causes magnetic saturation, causing part of the power to be escaped into the air.
Plate material – mild steel attracts best. Alloy admixtures lower magnetic permeability and holding force.
Surface quality – the smoother and more polished the plate, the better the adhesion and higher the lifting capacity. Unevenness acts like micro-gaps.
Thermal environment – heating the magnet causes a temporary drop of induction. Check the maximum operating temperature for a given model.

Holding force was measured on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, in contrast under shearing force the holding force is lower. Additionally, even a small distance between the magnet and the plate reduces the holding force.

Safety rules for work with NdFeB magnets

Crushing force

Danger of trauma: The attraction force is so immense that it can cause blood blisters, pinching, and even bone fractures. Protective gloves are recommended.

Threat to navigation

An intense magnetic field disrupts the functioning of compasses in smartphones and navigation systems. Keep magnets near a smartphone to avoid breaking the sensors.

Safe operation

Before starting, check safety instructions. Uncontrolled attraction can break the magnet or hurt your hand. Think ahead.

Cards and drives

Intense magnetic fields can destroy records on credit cards, hard drives, and other magnetic media. Keep a distance of at least 10 cm.

Eye protection

Despite metallic appearance, neodymium is brittle and cannot withstand shocks. Avoid impacts, as the magnet may crumble into hazardous fragments.

This is not a toy

Product intended for adults. Small elements can be swallowed, causing intestinal necrosis. Store away from children and animals.

ICD Warning

For implant holders: Powerful magnets disrupt medical devices. Maintain at least 30 cm distance or request help to work with the magnets.

Heat sensitivity

Monitor thermal conditions. Heating the magnet above 80 degrees Celsius will permanently weaken its magnetic structure and strength.

Sensitization to coating

Medical facts indicate that the nickel plating (the usual finish) is a strong allergen. If you have an allergy, avoid direct skin contact and select coated magnets.

Flammability

Fire hazard: Neodymium dust is highly flammable. Do not process magnets without safety gear as this may cause fire.

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

MPL 20x8x4 / N38 - lamellar magnet

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MPL 20x8x4 / N38 - lamellar magnet

Magnetic properties of material N38

Physical properties of sintered neodymium magnets Nd2Fe14B at 20°C

Physical analysis of the product - data

1. Wall mount (shear)

2. Efficiency vs thickness

3. Power loss vs temp

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

Elemental analysis

Sustainability

Force (pull)

Magnetic Induction

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Advantages and disadvantages of Nd2Fe14B magnets.

Pros

Cons

Lifting parameters

Maximum magnetic pulling force – what it depends on?

Practical lifting capacity: influencing factors

Crushing force

Threat to navigation

Safe operation

Cards and drives

Eye protection

This is not a toy

ICD Warning

Heat sensitivity

Sensitization to coating

Flammability

Physical properties of sintered neodymium magnets Nd₂Fe₁₄B at 20°C

Advantages and disadvantages of Nd₂Fe₁₄B magnets.