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.

The post What are the properties of conductive thread? 6 common properties appeared first on Electronic Guidebook.

Metallic thread, or conductive thread opens the doors to new projects where conventional wire would not be a suitable option.

Some of these applications include sewing on fabrics, embroidery art, creating flexible circuits, wearable art and much more.

But, is metallic thread conductive? Yes, metallic thread is conductive as it is used in electronic circuits where it needs to be able to allow current to flow. Conductive materials like copper, stainless steel allow current to flow whereas insulators inhibit the flow of current. Metallic thread is composed of material like stainless steel which makes it conductive. 

How is metallic thread conductive?

To better understand why metallic thread is conductive, let’s take a brief look at conductive materials. 

Conductors are certain types of materials that allow the flow of charge (current) in different directions.

The flow of charge happens when an electron of an atom in the conductor transfers its energy to it’s neighbour. 

Think of it like when you stack dominos and knock them over. 

Insulators on the other hand inhibit (do not allow) the flow of charge. 

The main reason for conductors being able to ‘conduct’ electrical current is that the outer electrons of the atoms in conductors are loosely bound and therefore easier to move through that particular material.

Insulators have electrons that are tightly bound to their atoms making it harder to traverse through the material. 

What materials are conductive?

Some materials are more conductive than others due to the fact that the outer electrons are held on less tighter to their atoms. 

How conductive a material is, therefore allowing it to transfer electrons more effectively is determined by its Electrical Conductivity which is measured in Siemens per meter (S/m).

Therefore, the higher the electrical conductivity of a material, the less resistance is present allowing for a freer flow of charge. 

Metals are one of the most conductive materials known, which is why they are used to create wires, components, circuit boards in electrical and electronic applications. 

Below is a table of common metals and their electrical conductivity (irom highest to lowest) at 20°C (this is because temperature can affect the electrical conductivity). 

What is metallic thread made of?

So, of the many metals available, which ones are most commonly used  to make metallic thread conductive?

While there are a range of metallic threads available made using a variety of different conductive metals, the most common metals used are Silver and Stainless steel.

Silver coated metallic threads

The first of the two common metals used to make metallic thread conductive is Silver.

This metallic thread is made by coating a nylon based thread with silver.

Silver coated metallic threads vary in their resistance and therefore need to be used in the right applications. 

Using it for large scale projects like a curtain or blanket, will require more thread which will increase the resistance. 

Smaller projects like t-shirts would be a better application to use silver coated metallic thread. 

Unfortunately, due to having a nylon core, this type of metallic thread cannot be soldered, as the high heat of the soldering iron will melt the solder. 

Stainless steel metallic threads

The next metal that is most commonly used to make metallic threads conductive is Stainless Steel. 

Unlike silver coated metallic thread, this type does not have a core material that is coated. 

This means that it is entirely made up of stainless steel.

As you can imagine, this is going to make it a lot harder to sew as it is not going to be very flexible.

But, compared to silver coated metallic thread, it has a much lower resistance making it ideal for larger projects. 

Another advantage of the stainless steel metallic thread is that you can solder it since it does not have a core like nylon which will melt.

Selecting the right conductive metallic thread for your project

So, your next project requires some metallic thread. But, which is the best one for your project?

As we saw above, both the metallic threads have their advantages and disadvantages.

Selecting the right one comes down to the needs of the project as well as your preferences. 

Below are some criteria to consider when trying to figure out which metallic thread to choose;

Size of the project

Resistance is the biggest issue here. Since stainless steel metallic thread has lower resistance of the two, it is a better option for bigger projects. As more thread you use, the resistance is going to increase as well.

Whether you need to solder the metallic thread

If you need to solder, silver coated metallic thread is not going to cut it. Again, stainless steel is your best option.

Will there be a lot of sewing involved

If your project requires a lot of sewing, it is going to be very frustrating trying to do so with stainless steel metallic thread, as it is not very flexible. This time silver coated thread is your best option.

Selecting the right metallic thread might not come down to just one criteria, it might come down two or all three. 

How can you check if metallic thread is conductive or not?

Maybe you have just bought some metallic thread that does not come with any datasheet, or specifications and are unsure if it is conductive or not.

Is there a way to check whether this thread you have is conductive?

Yes, you can check if a metallic thread is conductive by using a multimeter. 

Multimeters have a function known as the ‘Continuity test’ which allows you to test two points in a circuit, piece of wire, metal, etc, to ensure a complete path exists between these two points to allow current to flow. 

For example, the diagrams below show two pieces of wire. 

Diagram A shows a wire that is broken in the middle. If we were to test the wire for continuity between points X and Y, the multimeter would not indicate any continuity as the path is not complete.

However, if we were to test the wire in Diagram B between points X and Y, the multimeter would indicate continuity as a complete path exists.

A note to be made is that the continuity test only works with conductors. 

Therefore if you have metallic thread and it is not conductive, the multimeter continuity test will indicate so. 

Can conductive metallic thread  get really hot? 

Since metallic thread is used in applications where it will be sewn into fabric, as well as worn in certain wearable projects, it is a good idea to think how much current will pass through them.

The more current that passes through, the hotter the metallic thread is going to get which will increase the chance of burns or things catching fire. 

Ohm’s law is the relationship between voltage, current and resistance which can be seen in the following equation; V = IR.

As the resistance of a material decreases, the current increases (which will cause it to get hotter).

Adding a load like a Light Emitting Diode with a resistor will increase the resistance thereby decreasing the current. 

A multimeter will come in handy here again as you can test the resistances of your circuit as well as the amount of current present.

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