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UMGW 20x15x7 [M4] GW / N38 - magnetic holder internal thread

magnetic holder internal thread

Catalog no 180316

GTIN/EAN: 5906301813729

5.00
Load capacity 9.00 kg / 88.26 N
Diameter Ø
20 mm [±1 mm]
Height
15 mm [±1 mm]
Height
7 mm [±1 mm]
Weight
15.5 g
Magnetization Direction
↑ axial
Coating
[NiCuNi] Nickel

How we measure these parameters — certificates and measurements

technical parameters »

5.28 zł net / pcs

6.49 zł with VAT (23% VAT) / pcs

price for transport

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price from 1 pcs
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price from 100 pcs
4.96 zł
6.10 zł
price from 300 pcs
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5.72 zł

Frequently asked questions

How much will a magnetic holder hold in practice?
The catalogue value assumes full contact with smooth steel at least 10 mm thick and a perpendicular pull. Thinner sheet, paint, rust and surface irregularities reduce it considerably: on 1 mm sheet about half remains. Lifting and vertical mounting call for an additional safety margin.
Will a holder work on stainless steel?
Not on austenitic grades 304 and 316 — they are effectively non-magnetic. It will not work on aluminium, copper or brass either. Those materials need a mechanical gripper.
Which coating for which conditions?
Nickel-copper-nickel (NiCuNi) is the standard and covers most applications. Epoxy is used for damp environments and outdoor work, zinc is sufficient for dry interiors. Holders in a steel housing or in rubber also protect the magnet against impact.

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.

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Product card - UMGW 20x15x7 [M4] GW / N38 - magnetic holder internal thread

Specification / characteristics - UMGW 20x15x7 [M4] GW / N38 - magnetic holder internal thread

properties
properties values
Cat. no. 180316
GTIN/EAN 5906301813729
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 20 mm [±1 mm]
Height 15 mm [±1 mm]
Height 7 mm [±1 mm]
Weight 15.5 g
Magnetization Direction ↑ axial
Load capacity ~ ? 9.00 kg / 88.26 N
Coating [NiCuNi] Nickel
Manufacturing Tolerance ±1 mm

Magnetic properties of material N38

Specification / characteristics UMGW 20x15x7 [M4] GW / N38 - magnetic holder internal thread
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 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
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: 180316-2026
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The steel housing shields the magnetic field from the sides and top, directing all its power downwards (to the active side). Moreover, the metal housing protects the brittle neodymium magnet from cracking upon impact. The threaded hole allows creating a functional mounting point in seconds.
The most important rule is choosing the appropriate length of the screw being screwed in. Neodymium magnets are brittle, and direct pressure from a screw can cause them to crack or detach. It is worth securing the thread with thread glue if the connection is to be durable and resistant to vibrations.
They are used for fixing sensors, lamps, rating plates, machine guards, and installations. They enable creating demountable connections that can be easily moved. Ideal for fixing lighting on machine tools and welding tables.
This value applies to perfect adherence with the entire magnet surface. With thin sheets (e.g., car body, fridge casing), the force will be much smaller because steel cannot absorb the entire magnetic field. We always recommend choosing a magnet with power reserve, especially if the surface is not ideal.
Steel cups are usually coated with a layer of nickel (shiny) or zinc (matte/bright), providing basic protection. In rain and frost, the coating may degrade over time if not protected. The whole is well protected for standard workshop and industrial applications.

Strengths as well as weaknesses of rare earth magnets.

Benefits

Besides their durability, neodymium magnets are valued for these benefits:
  • They have stable power, and over around ten years their attraction force decreases symbolically – ~1% (in testing),
  • Magnets very well defend themselves against loss of magnetization caused by ambient magnetic noise,
  • The use of an refined layer of noble metals (nickel, gold, silver) causes the element to present itself better,
  • They are known for high magnetic induction at the operating surface, which improves attraction properties,
  • Thanks to resistance to high temperature, they can operate (depending on the form) even at temperatures up to 230°C and higher...
  • Thanks to the ability of accurate shaping and adaptation to specialized solutions, NdFeB magnets can be produced in a wide range of geometric configurations, which amplifies use scope,
  • Significant place in advanced technology sectors – they are utilized in data components, motor assemblies, medical devices, as well as multitasking production systems.
  • Relatively small size with high pulling force – neodymium magnets offer impressive pulling force in small dimensions, which allows their use in miniature devices

Cons

Disadvantages of NdFeB magnets:
  • They are prone to damage upon heavy impacts. To avoid cracks, it is worth protecting magnets in a protective case. Such protection not only protects the magnet but also increases its resistance to damage
  • We warn that neodymium magnets can lose their power at high temperatures. To prevent this, we advise our specialized [AH] magnets, which work effectively even at 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 those in rubber or plastics, which secure oxidation as well as corrosion.
  • We recommend cover - magnetic mechanism, due to difficulties in realizing threads inside the magnet and complicated shapes.
  • Potential hazard to health – tiny shards of magnets pose a threat, if swallowed, which becomes key in the context of child health protection. It is also worth noting that small elements of these products can complicate diagnosis medical in case of swallowing.
  • Higher cost of purchase is a significant factor to consider compared to ceramic magnets, especially in budget applications

Holding force characteristics

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

The force parameter is a measurement result conducted under standard conditions:
  • on a base made of structural steel, optimally conducting the magnetic flux
  • whose transverse dimension equals approx. 10 mm
  • with a surface perfectly flat
  • with direct contact (no paint)
  • for force acting at a right angle (pull-off, not shear)
  • in temp. approx. 20°C

Impact of factors on magnetic holding capacity in practice

In practice, the real power results from several key aspects, ranked from crucial:
  • Space between surfaces – every millimeter of separation (caused e.g. by veneer or unevenness) significantly weakens the pulling force, often by half at just 0.5 mm.
  • Force direction – remember that the magnet holds strongest perpendicularly. Under sliding down, the capacity drops significantly, often to levels of 20-30% of the maximum value.
  • Element thickness – for full efficiency, the steel must be adequately massive. Thin sheet limits the attraction force (the magnet "punches through" it).
  • Material type – ideal substrate is pure iron steel. Cast iron may generate lower lifting capacity.
  • Surface quality – the more even the surface, the larger the contact zone and higher the lifting capacity. Unevenness acts like micro-gaps.
  • Thermal conditions – NdFeB sinters have a negative temperature coefficient. At higher temperatures they are weaker, and in frost they can be stronger (up to a certain limit).

Lifting capacity was assessed using a polished steel plate of optimal thickness (min. 20 mm), under perpendicular pulling force, in contrast under attempts to slide the magnet the lifting capacity is smaller. In addition, even a small distance between the magnet’s surface and the plate decreases the holding force.

Safe handling of neodymium magnets
Avoid contact if allergic

Medical facts indicate that nickel (the usual finish) is a potent allergen. For allergy sufferers, refrain from touching magnets with bare hands or select coated magnets.

Pacemakers

Health Alert: Strong magnets can deactivate heart devices and defibrillators. Do not approach if you have medical devices.

Conscious usage

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

Eye protection

Neodymium magnets are ceramic materials, meaning they are prone to chipping. Collision of two magnets leads to them shattering into small pieces.

Physical harm

Watch your fingers. Two powerful magnets will join immediately with a force of massive weight, crushing anything in their path. Exercise extreme caution!

Machining danger

Dust produced during grinding of magnets is combustible. Do not drill into magnets unless you are an expert.

Thermal limits

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

Threat to navigation

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

Magnetic media

Do not bring magnets close to a wallet, computer, or screen. The magnetic field can destroy these devices and wipe information from cards.

Do not give to children

Absolutely store magnets out of reach of children. Ingestion danger is high, and the effects of magnets connecting inside the body are fatal.

Security! Looking for details? Read our article: Why are neodymium magnets dangerous?