← previous
next →
Product available Ships in 2 days CO2 GPSR PPWR REACH

UMT 29x38 black / N38 - board holder

board holder

Catalog no 230284

GTIN/EAN: 5906301814368

5.00
Diameter Ø
29 mm [±1 mm]
Height
38 mm [±1 mm]
Weight
6 g
Coating
[NiCuNi] Nickel

How we measure these parameters — certificates and measurements

product details »

5.54 zł net / pcs

6.81 zł with VAT (23% VAT) / pcs

price for transport

bulk discounts:

Need more?
Quantity
Net
Gross
price from 1 pcs
5.54 zł
6.81 zł
price from 100 pcs
5.21 zł
6.41 zł
price from 150 pcs
4.88 zł
6.00 zł

Frequently asked questions

How many sheets of paper will one magnetic pin hold?
The category description quotes <strong>up to 20 sheets of A4</strong>, and that is the number to start from. It is not fixed: a magnet holds more firmly on a thicker base — a fridge door or a solid whiteboard backing gives more than the thin sheet behind a cheap dry-wipe board. Paper matters too: twenty sheets of office weight is not the same as twenty sheets of coated stock. For thicker stacks and folders take a larger size, 20x25 or 29x38 mm — a bigger contact area than 12x20.
Will a magnetic pin stick to any board - whiteboard, glass, cork?
No, not to every surface — a magnet only holds on a ferromagnetic material, which usually means whiteboards and glass boards that have a steel sheet underneath. Plain glass without a metal backing won't attract the magnet at all. Cork boards mostly lack a metal layer too, so the pin won't stick unless the manufacturer specifically states the board is magnetic. Before buying, a simple test helps — try any magnet against the board in the shop or at home.
Will the magnet leave a mark or scratch the board or the fridge?
No, under normal use the pin leaves no lasting mark or scratch — the bottom of the magnet has an ergonomic, smooth shape designed for contact with smooth surfaces like a lacquered fridge door or a laminated board. The risk appears only when sliding the magnet across a surface with trapped grit or other hard particles caught between the base and the board — that can cause a light scratch, the same as with any object dragged across a painted surface. Wiping the magnet's base regularly removes this risk.
What is the difference between the 12x20 and 20x25 sizes, and which one suits an office?
The main difference is holding strength and grip comfort — the UMT 20x25 has a larger magnet surface, so it holds a thicker stack of sheets more firmly and is easier to grab with your fingers. The UMT 12x20 is compact and works better where board space is tight, for example with many small notes side by side. For a typical office board holding a few sheets and schedules, both sizes work fine — the choice mainly comes down to whether holding strength or fitting more pins side by side matters more.
Are magnetic pins suitable for large-format maps and plans?
Yes, they work well for that — the larger UMT 20x25 variant is well suited to maps and plans hung on magnetic boards in offices, on construction sites, or in planning rooms, since it holds heavier, stiffer paper better than the smaller pin. For a large format, it helps to place several pins along the corners and edges of the plan rather than just one in the center — this spreads the pressure and prevents the paper from sagging under its own weight.

Guides from the knowledge base

Want to talk magnets?

Call us now +48 888 99 98 98 alternatively let us know using contact form the contact section.
Specifications and structure of a neodymium magnet can be estimated using our power calculator.

Order by 14:00 and we’ll ship today!

Detailed specification - UMT 29x38 black / N38 - board holder

Specification / characteristics - UMT 29x38 black / N38 - board holder

properties
properties values
Cat. no. 230284
GTIN/EAN 5906301814368
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 29 mm [±1 mm]
Height 38 mm [±1 mm]
Weight 6 g
Coating [NiCuNi] Nickel
Manufacturing Tolerance ±1 mm

Magnetic properties of material N38

Specification / characteristics UMT 29x38 black / N38 - board holder
properties values units
Remanence Br ? 12.2-12.6 kGs
Remanence Br ? 1220-1260 mT
Coercivity bHc ? 10.8-11.5 kOe
Coercivity bHc ? 860-915 kA/m
Intrinsic coercivity iHc ≥ 12 kOe
Intrinsic coercivity iHc ≥ 955 kA/m
Energy product BHmax ? 36-38 BH max MGOe
Energy product BHmax ? 287-303 BH max KJ/m
Maximum working 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 310 °C
Curie Temperature TF 590 °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 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%

Ecology and recycling (GPSR)

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: 230284-2026
Quick Unit Converter

Pulling force

Magnetic Field

Type data in any box, to see the remaining units change instantly.

See also products

UMGW 42x20x9 [M6] GW / N38 - magnetic holder internal thread
Product available Ships in 2 days

UMGW 42x20x9 [M6] GW / N38 - magnetic holder internal thread

33.95 zł brutto / pcs
SMZR 25x150 / N52 - magnetic separator with handle
Product available Ships in 2 days

SMZR 25x150 / N52 - magnetic separator with handle

430.50 zł brutto / pcs
SM 32x425 [2xM8] / N42 - magnetic separator
Product available Ships in 2 days

SM 32x425 [2xM8] / N42 - magnetic separator

1414.50 zł brutto / pcs
UMP 135x40 [M10+M12] GW F600 Lina / N38 - search holder
Product available Ships in 2 days

UMP 135x40 [M10+M12] GW F600 Lina / N38 - search holder

649.99 zł brutto / pcs
This shape makes operating a whiteboard convenient, fast, and does not break nails. Inside the plastic housing is a very strong neodymium magnet, not weak ferrite. It's a professional choice for office, school, conference room, and home.
Despite inconspicuous size, one pin with a neodymium magnet can hold even 15-20 A4 paper sheets. They guarantee that your notes and important information will stay in place.
They work well as markers on maps, scoreboards, planners, or Kanban systems. Available vivid colors facilitate information coding, prioritizing, and task organization. Note: Special, even stronger neodymium magnets are needed for glass boards.
Caution should be exercised and the product kept away from infants. For older children, they are a great scientific aid for physics experiments.
Both single-color sets (e.g., 10 pcs) and mix variants (rainbow) are available. Translucent variants give an interesting, modern visual effect.

Strengths and weaknesses of rare earth magnets.

Pros

In addition to their long-term stability, neodymium magnets provide the following advantages:
  • They retain full power for around 10 years – the loss is just ~1% (in theory),
  • Neodymium magnets are highly resistant to magnetic field loss caused by external magnetic fields,
  • A magnet with a smooth gold surface has an effective appearance,
  • The surface of neodymium magnets generates a strong magnetic field – this is a distinguishing feature,
  • Thanks to resistance to high temperature, they are able to function (depending on the shape) even at temperatures up to 230°C and higher...
  • Thanks to versatility in designing and the ability to modify to unusual requirements,
  • Huge importance in innovative solutions – they serve a role in data components, electric drive systems, diagnostic systems, as well as modern systems.
  • Thanks to efficiency per cm³, small magnets offer high operating force, with minimal size,

Weaknesses

What to avoid - cons of neodymium magnets: application proposals
  • Brittleness is one of their disadvantages. Upon intense impact they can break. We recommend keeping them in a special holder, which not only secures them against impacts but also raises their durability
  • Neodymium magnets decrease their power 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 stability even at temperatures up to 230°C
  • They oxidize in a humid environment. For use outdoors we suggest using waterproof magnets e.g. in rubber, plastic
  • Due to limitations in realizing threads and complicated shapes in magnets, we propose using cover - magnetic mechanism.
  • Possible danger related to microscopic parts of magnets can be dangerous, when accidentally swallowed, which becomes key in the context of child safety. Furthermore, small elements of these devices are able to be problematic in diagnostics medical in case of swallowing.
  • With mass production the cost of neodymium magnets is a challenge,

Lifting parameters

Maximum lifting capacity of the magnet – what contributes to it?

Magnet power was determined for optimal configuration, taking into account:
  • on a plate made of structural steel, effectively closing the magnetic field
  • with a thickness of at least 10 mm
  • with a surface perfectly flat
  • without the slightest clearance between the magnet and steel
  • during pulling in a direction perpendicular to the mounting surface
  • at room temperature

Impact of factors on magnetic holding capacity in practice

In real-world applications, the actual holding force depends on a number of factors, ranked from the most important:
  • Clearance – existence of any layer (rust, tape, air) interrupts the magnetic circuit, which reduces capacity steeply (even by 50% at 0.5 mm).
  • Direction of force – highest force is obtained only during perpendicular pulling. The shear force of the magnet along the plate is usually many times smaller (approx. 1/5 of the lifting capacity).
  • Base massiveness – too thin sheet causes magnetic saturation, causing part of the power to be wasted into the air.
  • Material type – the best choice is high-permeability steel. Stainless steels may attract less.
  • Surface condition – ground elements guarantee perfect abutment, which improves force. Rough surfaces reduce efficiency.
  • Temperature influence – high temperature weakens magnetic field. Too high temperature can permanently demagnetize the magnet.

Holding force was tested on a smooth steel plate of 20 mm thickness, when a perpendicular force was applied, whereas under attempts to slide the magnet the load capacity is reduced by as much as fivefold. Additionally, even a slight gap between the magnet’s surface and the plate lowers the load capacity.

Safety rules for work with neodymium magnets
No play value

Always keep magnets away from children. Choking hazard is high, and the effects of magnets clamping inside the body are very dangerous.

Danger to pacemakers

Individuals with a pacemaker should keep an absolute distance from magnets. The magnetic field can stop the functioning of the life-saving device.

Protect data

Device Safety: Neodymium magnets can damage data carriers and sensitive devices (pacemakers, medical aids, mechanical watches).

Do not drill into magnets

Combustion risk: Rare earth powder is highly flammable. Avoid machining magnets in home conditions as this may cause fire.

Heat warning

Avoid heat. NdFeB magnets are sensitive to temperature. If you need resistance above 80°C, inquire about special high-temperature series (H, SH, UH).

Caution required

Before use, check safety instructions. Sudden snapping can destroy the magnet or hurt your hand. Think ahead.

Keep away from electronics

GPS units and smartphones are highly susceptible to magnetism. Close proximity with a powerful NdFeB magnet can ruin the sensors in your phone.

Avoid contact if allergic

Some people have a sensitization to Ni, which is the typical protective layer for NdFeB magnets. Frequent touching can result in dermatitis. We suggest use protective gloves.

Finger safety

Risk of injury: The attraction force is so immense that it can cause blood blisters, pinching, and broken bones. Protective gloves are recommended.

Fragile material

Despite the nickel coating, the material is brittle and cannot withstand shocks. Avoid impacts, as the magnet may crumble into hazardous fragments.

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