Wires help us carry current from one point to another in many different electrical and electronic applications.
But, normal wire that is used in these applications is not very flexible and cannot be stitched to clothing or fabric.
Conductive thread has the ability to carry the current the same way normal wire can but with the added benefit of being able to be stitched into fabrics.
You can create flexible circuits using conductive thread without having to solder.
This opens up new avenues for a plethora of applications.
But, what are the properties of conductive thread? Below are some of the properties of conductive thread:
- Low resistance
- Decent conductor
- Flexible
- Light
- Sewable (by hand or machine)
- Blends in well (does not stick out like a sore thumb)
Different types of conductive thread
When discussing the properties of conductive thread, we first need to talk about the different types of conductive thread available, as each type will differ in properties.
While there are many different types of conductive thread available that are constructed with various materials, there are two that are more popular than others.
The two main conductive threads are ; Silver coated and Stainless steel.
The properties that I mentioned above do not apply to both types of conductive thread as they are both constructed differently.
However, some of the properties hold true for both silver coated and stainless steel conductive thread.
Silver coated conductive thread
This thread has a nylon thread at its core which is coated with silver.
The coating of silver gives the thread its conductivity.
Resistance of silver coated conductive thread can be an issue as it can vary a great deal with length.
The more conductive thread that is used the higher the resistance. So, first check how much thread you will need to use and measure the resistance.
Also, since it has a nylon thread core, this type of thread cannot be soldered as the nylon will melt with the high heat generated by the soldering iron.
Stainless steel conductive thread
The next main type of conductive thread used is Stainless Steel.
This type of conductive thread does not have a nylon core. It is constructed fully out of stainless steel.
Due to this, they are less flexible than silver coated threads making them more difficult to sew.
However, the upside is that they have a much lower resistance making them great for larger projects.
Also, they can be soldered as the stainless steel will not melt with the high temperatures of the soldering iron.
6 Properties of conductive thread
Let’s take a closer look at the different properties of conductive thread.
Properties of conductive thread #1: Low resistance
Electrical resistance is the measure of a material’s (mainly conductors) ability to ‘resist’ current which flows through it.
The unit of measure for electrical resistance is known as Ohms.
As the resistance of a material increases the less current can flow through it, and vice versa.
So, why is resistance a property we should be concerned with when it comes to conductive thread?
If the conductive thread has a high resistance, it is going to limit the current that can flow through it.
Also higher resistant materials will get hotter as more energy is required to get past it. A lot of energy is wasted in the form of heat.
The lower the resistance the better.
When it comes to conductive threads, both have low resistances.
However, if a lot of thread is needed in a project, it is advisable to use stainless steel as opposed to silver coated conductive thread.
Properties of conductive thread #2: Decent conductor
A conductor is a material that allows heat and electricity to flow more freely in multiple directions.
Compared to an insulator, the electrons in a conductor are held on more loosely to their atoms which lets them move around easier and pass their energy to other electrons.
With a conductive thread we are more concerned with its ability to allow current to flow as these currents need to be carried around different parts of flexible circuits through conductive thread.
Like how we can measure how much a material can resist current by the quantity of resistance (ohms) we can measure how easily current can flow through a conductor through the quantity Electrical conductance (siemens).
The higher electrical conductance of a material the more efficient it is at allowing current to flow.
Silver has the highest electrical conductivity of all metals sitting at 62.1 x 106 siemens/m.
Stainless steel sits near the bottom of the list with an electrical conductivity of 1.37 x 106 siemens/m.
So, you can see that the stainless steel doesn’t have the highest conductivity making its variety of conductive thread a decent conductor.
But what about silver coated conductive thread?
Silver does have the highest electrical conductance.
The physical dimensions of metals play a large part in their electrical conductance. Things like diameter of a wire, surface area, length etc.
Due to the construction of conductive thread, it is limited by its physical dimension (as it needs to be able to be sewed by hand as well as a sewing machine).
It is also created with a lot of strands (which make up the thread). This limits its conductivity compared to a solid piece of wire.
Properties of conductive thread #3: Flexible
Conductive threads have a variety of applications.
One main one is E-textiles, which are fabrics that have been enhanced with digital components like Light Emitting Diodes (LEDs), sensors, batteries etc.
Normal circuit boards are sturdy and have a solid base for components and wires so there is less chance of things breaking due to movement.
Fabrics on the other hand are materials that are flexible and move freely in any given direction.
So, using conventional wires in e-textiles is going to make the fabric stiff and harder to move in.
Another one of conductive threads’ great properties is its flexibility.
Rather than restricting the movement of the fabric, it moves with it while still allowing current to flow.
Properties of conductive thread #4: Light (weight)
If you are going to be using a lot of conductive thread you do not want its weight to add up.
This added weight can be detrimental to your project.
For example, imagine you were designing a suit for a dancer that lights up everytime they move.
You want this suit to be as light as possible otherwise the dancer will not be able to perform their dance routine the same way they did without the suit.
Lucky for us conductive thread is light.
A 30ft (9.1m) roll can weigh up to only 60g!
Properties of conductive thread #5: Sewable
I wasn’t sure if sewable was a word, but a quick google search confirmed by doubts.
So the 4th property of conductive thread is that it is sewable.
We have established that conductive thread is used with fabrics like t-shirts, dresses, curtains, quilts etc.
Creating circuits on fabrics is one hard task if you cannot sew things. Trust me!
I have tried using duct tape and hot glue.
While not being aesthetically pleasing, it isn’t very functional either.
So, the property of the conductive thread being sewable is a great advantage.
Note, the stainless steel conductive thread is a bit harder to stitch. Opt for the silver coated conductive thread if you need to do a lot of sewing.
Properties of conductive thread #6: Blends in
I mentioned above that using hot glue or duct tape isn’t very aesthetically pleasing.
Aesthetics is a big deal when it comes to e-textiles.
You might be creating a cosplay costume, or designing a light up dress for a fashion show.
You want your creation to look presentable.
The last and final property of the conductive thread is that it blends in well with whatever you stitch it to and does not stick out like a sore thumb.
Do all conductive thread have the same properties
No, all conductive threads do not have the same properties.
Due to the way they are constructed, and the materials used to create them, the properties of conductive thread will vary from one type to the next.
Below is a table showing the different properties and which of the two main types of conductive threads have that certain property.
| Silver coated conductive thread | Stainless steel conductive thread | |
| Low resistance | The less thread the better | Yes |
| Decent conductor | Yes | Less than silver |
| Flexible | Yes | Not so much |
| Light | Yes | Yes |
| Blends in well | Yes | Yes |
