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Hollow Conductors

Hollow Conductors

Luvata has been manufacturing copper hollow conductors for the most demanding applications for nearly sixty years.  Hollow conductors are sometimes referred to as conductors, hollow wire, hollow magnet wire, square copper tube or rectangular copper tube.

Applications for Hollow Conductors

  • Electric vehicles (EVs) / stator direct cooling
  • MRI devices
  • Magnets for high energy physics applications
  • Particle accelerators
  • Generators
  • Induction furnaces
  • Plasma research devices
  • Electrodynamic vibration test systems
  • Ion implantation units for the microcircuit industry
  • High gradient separators
  • Waveguides


Electric vehicles (stator direct cooling)

Our hollow conductors provide new possibilities to cool down electric motors. The internal cooling hole on the stator windings enables increased power and torque. Cooling with air improves the performance significantly and liquid cooling even more.

Widest range of tools on the market

Our long history in making hollow conductors has given us thousands of tools for creating most sizes of conductors with very short lead times.  The sizes start from 4 x 4 mm (< 0.1 kg/m) and continue up to above 100mm in width (>20 kg/m).  We can also supply conductors in small quantities for testing and for prototype purposes. 


Material for Hollow conductors

Our hollow conductors are made from high-conductivity, oxygen-free copper OF-OK®, which is a high purity copper with an electrical conductivity of at least 100% IACS.  OF-OK oxygen-free copper used in our hollow conductors is cast in our own foundry in electric furnaces using selected high purity raw materials.  This means we can control the whole manufacturing process from casting to signing the inspection certification, and ensure the consistency of our product from batch to batch.

If higher softening temperatures or creep strengths are required, we recommend the use of silver bearing copper grades CuAg 0.03% or CuAg 0.1%, which are based on OF-OK copper. These copper grades offer high electrical and thermal conductivity and their freedom from oxygen ensures excellent brazeability and weldability, making them superior to oxygen-bearing copper grades.

The longest hollow conductor in the world

Every joint in a water cooled magnet is a potential source of leakage. The longer each individual coil is, the more the risk is reduced.

With the aim of eliminating the joints within the magnet altogether, we have developed an extremely long Mileon™ jointless hollow conductor. The length of these coils, rather than being measured in meters, is now measured in hundreds, or even in thousands of meters. The coil weight can be as high as 1700 kg - a single coil, jointless.


Mileon coil advantages

  • No joints
  • Highest quality copper
  • Less copper wastage


Mileon coils are manufactured using only oxygen-free copper, and are subject to the same stringent quality criteria that we apply to our other hollow conductor products.

Using Mileon coils means that less scrap is generated in the magnet manufacturing process, and expensive copper is saved. The longer coils also provide increased flexibility in production compared with shorter coils which are cut to pre-determined lengths.

Mileon coils are delivered on large wooden spools, and compared with traditional coils, less packaging material is required.  This means there is less weight to be transported and thus has a reduced impact on the environment.


Online tool list for dimensions and shapes

With the online hollow conductors tool list and calculator you can browse the old and most recent hollow-conductor profiles.

You also have the opportunity to design your own hollow conductor using the calculator, which provides the basic geometrical values, metric weight and cross-sectional areas of your own conductor design.

We have now also a printable tool list for you available in the resources.


Visit the resources

Hollow Conductors delivery forms

MileonTM jointless hollow conductor Up to 1700 kg depending on dimensions, delivered on wooden reel.
Loose coils or pancake coils Max 50 to 150 kg depending on the dimensions
Spools for small sizes Plywood spools
Straight lengths up to 12 meters



Online tool list and calculator

You can make your own calculations with our Tool calculator, which provides the basic geometrical values, metric weight and cross-sectional areas of your own conductor design.

Hollow conductors tool list

Hollow conductors tool calculator

Printable hollow conductors tool list, A4

Printable hollow conductors tool list, US


Copper Hollow Conductors
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The newsletter for Mileon jointless hollow conductors

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