Sewing Machine Tension Guide

Getting the right tension on the sewing machine is one of the most common issues that most people complain of. Even the experts tend to get a tad bit confused at times in this department, so a beginner can’t be blamed. But what is tension in terms of a sewing machine?

Thread tension refers to the amount of thread passing through a sewing machine for creating stitches. As you increase the amount of thread in the stitches, the stitches get looser, and vice versa.

If you have been struggling with getting the tension settings right on the machine, you have come to the right place. Read on to know every detail about thread tension.

A number of factors impact the tension settings on a sewing machine. And one of them is the type of fabric you are stitching. So, for instance, the tension settings when you are sewing fleece will not be the same as when you sew leather.

The following is a brief guide on the different tension settings to use for different fabric types.

Sewing Machine Tension Settings For Thick Fabric

The rule of the thumb is: the thicker your fabric, the higher the tension needs to be.

In this case, a higher tension will help to raise the lower threads to the fabric’s middle layers.

When stitching a thicker fabric, keep the tension set at 4 to 5 to get smooth stitches. 

Medium-heavy to medium fabrics, such as linen are good to go in this setting. Thicker upholstery fabrics might need longer stitches and higher tension settings. If yours is an automatic sewing machine, set that to the upper tension adjustments using thicker threads.

Sewing Machine Tension Settings For Denim

The normal setting remains at the middle, i.e., at 4.

A higher tension is important for something as tough and thick as denim. You will need to adjust it to a greater number by tuning the dial of the machine that is located at the top or front of it.

The ideal tension is up to 6 because it gets too high after that and starts pulling the top stitch to turn it into a flat line.

You will note that the bobbin stitches get cleared up at 6, but do not improve much beyond that. 

Sewing Machine Tension Settings For Polyester

Pointing out the right tension of threads to use to sew polyester can be a difficult job.

There are too many variables to consider in this case, such as the type of polyester you’ll be using. Set the machine to an upper tension of 4. This setting should cope with most kinds of polyester fabrics, and you will only need minor adjustments, if any.

Test it out on a piece of polyester and see if you are getting even stitches. Move the dial a notch if 4 is not getting you good stitches.

Sewing Machine Tension Settings For Lightweight Fabrics 

After knowing about the right machine tension settings for heavy fabrics, you have an idea now about what to do for lightweight fabrics. The simple rule to remember is that you loosen the tension in case of thin or lightweight fabrics.

The general setting, as mentioned before, stands at 4. You can go up to 3 or even two, depending on how thin the fabric is. Like you did previously, start at 4 and move down a notch at the time of sewing, if necessary.

Sewing Machine Tension Settings For Cotton

Sewing Machine Tension Settings For Cotton

In densely-woven fabric like duck cloth, denim, or batiks, the top thread has a higher level of friction. This is not the case in cotton, which has a loose weave.

Fabrics like knits and quilting cotton let the top thread to move along individual fibers present in the fabric with low friction. Therefore, the thread gets less tension at the time of forming the stitch.

So, cotton needs a moderate setting, which is generally around 3 to four. Start adjusting the tension settings on the upper tension before stitching.

Sewing Machine Tension Settings For Leather

Setting the tension for leather is a bit tricky. Tighten the top tension to a point where you pull each knot consistently to the top. Now, you will pass a point where you will get the right tension. So, start from a point of no tension and adjust by complete turns, while counting along the way.

After you have got the right setting for tension, set that to pull at the top. Then, start to back off the tension until the knot gets pulled in the hole. Remember the adjustments you have made at this point so that you can use them for future reference.  

Sewing Machine Tension Settings For Flannel

The quality of flannel you use can make a major difference in the machine tension and the kind of stitch you use. The price of the flannel and the thread count rises in tandem. 

In most cases, you need to loosen up the tension slightly and use a 3.0 mm stitch length (because shorter stitch lengths will get the fabric stretched). However, the standard tension of 4 works in case of most flannel fabrics found in the market.

Sewing Machine Tension Settings Setting For Fleece

You should always increase your stitch length to three mm and reduce the stitch tension. Reduce the presser foot dial if you are using it. Also, remember that if you do not adjust the stitch settings before you start, no one can save you from the thread nest that is coming.

Along with the tension settings, make sure you pay attention to the needle you use, and get a sharp one at that. Furthermore, beyond the tension, the issue with fleece is that it tends to shift, so get an extra pair of feed dogs if you can.

Sewing Machine Tension Settings For Satin

Sewing Machine Tension Settings For Satin

Satin is the kind of fabric that does not lend itself too well to tension. Naturally, it is not even the fabric you use for any skin-tight. Under tension, the seams become clearly visible. Then, the thread starts pulling larger holes as the tension rises. 

Thus, using excessive tension in the threads will make the seams pucker up and pull. So, dial back the tension and run a rough stitch on scraps until the results make you happy. Remember that the dial usually goes below the standard 4 in case of satin.

Sewing Machine Tension Settings For Stretchy Fabric

A “stretchy” fabric is any kind of cloth that you can stretch more than any other type of fabric. These types of fabrics are called knitted or woven. As such, stretch-woven variants, single-knits, and a number of double knits come under this group. You need to use the right tension settings for stitching the stretchy fabrics.

Materials like Lycra and elastane need a tension level of around 2 to 3. Make sure to be extra-cautious with the tension settings because anything looser or tighter than required would impact the seams considerably.

Machine Quilting Tension Settings

When you are using the wrong tension, it is easily identifiable by loops on its backing or over the quilt sandwich. With the right tension settings in your sewing machine, you will get almost identical stitches on the front and back of the work. You will notice no tugging through of your thread on any of the sides, especially at the sharp points and curves in the quilt.

The best thing you can do in this regard is to make a rough quilt sandwich and start with the standard tension setting. Move the knob up or down based on how the stitches look to you.

What Do The Tension Numbers Mean On A Sewing Machine?

What Do The Tension Numbers Mean On A Sewing Machine?

A sewing machine needs a bottom and top thread to put a correct stitch. The threads have to work harmoniously with one another to get interlinked right in the fabric’s middle. The lack of balance in this regard will make one thread pull another at the other side. It will lead to a poor-quality stitch that doesn’t hold.

There is a dial on the thread path of sewing machines that controls the tension for the top thread. Thus, ensure your thread sits perfectly between different tension discs while threading the machine. Failing to do this will make the machine put loose, wobbly stitches. So, the look is simply unattractive.

You will notice that this dial has numbers put on it, and you can turn the knob to change the tension. Most machines have this dial numbered from 0 to 9, i.e., loose to tight tension, respectively. Thus, while adjusting the tension on the upper thread of the machine, keep in mind that lower numbers mean looser (lower) tension. And the higher numbers mean tighter (higher) tension. 

Now, you need to change the settings of the dial to as many notches as you need to get the right kind of stitches.

How To Adjust Tension On Sewing Machine Bobbin?

How To Adjust Tension On Sewing Machine Bobbin?

Most sewing machines come with their bobbin tension set at a standard point. You are good to go with this standard setting, but that does not mean you will never have to change it. After all, you are not going to sew the same material again and again for the rest of your life, right?

Adjusting the tension on sewing machine bobbin is a three-step process that goes like this:

Step 1. Find The Screw For Tension Settings

Bobbin tension (otherwise called bottom tension) is usually set at a factory for all standard sewing threads. You would not need any adjustment for a greater part of your journey.

A small screw controls this tension that you can adjust. You’ll find it right beside the thread openings.

Did you find a small plate with the thread going through the hook? The little screw makes this plate change the thread tension.

Step 2. Start Adjusting Your Tension

This screw has zero markings so if you move it all the way suddenly from its actual position, reinstating it might be hard. Thus, use a black marker to mark its actual position.

Carry a small screwdriver to start making the adjustments. Also, such small screwdrivers come with many machines. Move this screw to its right for a tight tension and to its left for loosening the tension.

Step 3. Test Out The Results On Scraps

Insert a winded bobbin in the bobbin case before holding the end of the thread on one hand. Now, put the other hand below the bobbin to hold the thread and move it gently.

If the bobbin does not move an inch, its tension is way too tight. When the slides off, it shows a loose tension. Finally, if the case keeps moving only a little with each pull, you have the ideal tension.

Threading the needle is a good way to note the bobbin’s tension. Afterward, lower your presser foot and pull both the threads at one time. You get the ideal tension when they both come out evenly.

How To Fix Sewing Machine Tension Knob?

Sewing Machine Tension

Fixing the tension knob of your sewing machine seems like a job for the pros, isn’t it? In reality, it is not that big a deal. All you need to do is follow the given steps:

Step 1. Start With The Presser Bar Lever

Your first job is to lift the presser bar lever of the machine. Notice that at this point the tension discs are not pushing the top thread in any way.

Step 2. Loosen The Set Screws For The Tension

You might try to rotate the tension knob, but note that the thread tension remains unchanged. In this case, you will have to loosen the set screw to take out its tension assembly. Rotate the screw to the left to loosen it.

Step 3. Pull The Tension Knob Towards You

Now take off your machine’s thread tension assembly, and grip that with your fingers to pull it towards you.

Step 4. Mark The Sequence Assembly

The one thing you need to do is to mark the assembly sequence. So, some models of the machines come with several features. In case you contain no manual with schemes you need to ensure how things get back together.

You need to clean the machine part of the tensioner at the beginning and all the parts so that they can get back on in the right sequence. 

How To Replace Tension Assembly On Sewing Machine?

Though there are multiple types of tension assemblies, their way of work is similar across every machine. This tension assembly is important for adding resistance on the top part. The resistance makes sure the stitches stay in place. So, without tension assembly, the bottom and top thread won’t interlock properly. It makes for a really unattractive and weak seam.

The tension in the machine will differ depending on the fabrics you sew and the stitch you use. The usual goal is to get the equal resistance at the thread, until you’re top stitching. This only happens when you want those top tension a bit loose compared to the bottom.

Before starting the work, cut scrap from the intended fabric. Also, utilize the similar thread and stitches you want to use on the project and sew on a short test piece. On the sewing machines, the higher number refers to high resistance on the top thread.

If you can see bottom threads visible from over the fabric, though the top threads are not seen from the fabric’s bottom. Then, the tension dial goes higher. 

How To Adjust Tension On Old Singer Sewing Machine?

Adjust Tension On Old Singer Sewing Machine

Adjust Bottom Tension

The adjustment principle of its bottom tension is the same for every Singer machine. The spring remains a bit arched with small adjusting screws to control the spring pressure.

Take a look at that and know the amount of pull needed for the threads to move between the two.

Adjust Top Tension 

After setting the bottom tension properly, the top part needs to offer enough adjustment bands for the complete range of threads and materials to use.

In case the lower tension remains properly set, the machine will still sew, though the top tension might need to stay at the highest setting for compensation. It might cause loose or tight stitching or some thread break under this condition.

End note

And that’s it! You now have all the details you need to set the right tension, regardless of the fabric you use. Go ahead and try these tips now, and see for yourself.



I'm Jessica Flores, a professional fashion designer and an expert seamstress. Crafting has always been a deep-seated passion of mine, one that has flourished and evolved over the years. I've dedicated considerable time to both studying and practicing in the realm of fashion and sewing, amassing a wealth of experience and skills. It brings me great joy to share these insights and experiences with you all, hoping to inspire and foster a similar passion for the art of sewing.

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