Sewing Machine Tension: Know the Basics

Are You on the Road to Sewing Machine Tension Perfection? Let’s Do it Together

Sewing machine tension is a keyword of every sewing experience.

When you learn to sew, you need to get familiar with the machine tension dynamics, not only for pure knowledge but also to ‌tackle fixing tension on a sewing machine.

So keep reading to explore all there is to know about adjusting the tension on a sewing machine.

Sewing machine tension—basics

Before we learn how to adjust the tension on a sewing machine, we need to understand the essentials of sewing machine tension.

According to Artisan Stitch, what we mean by thread tension in the machine sewing process is the amount of thread that can pass through the machine to create the stitch. 

    • the more thread in the stitch, the looser the stitch,
    • the less thread in the stitch, the tighter the stitch;

Not surprisingly, the most desirable solution lies somewhere in the middle. 

Click below to see a neat video commentary on this dynamic delivered by Tobo with Professor Pincushion:

According to Threads Magazine, most machines have thread guides, tension disks, a tension regulator, and a bobbin case spring that controls the bobbin-thread tension. 

So let’s dig a little deeper with Artisan Stitch

A dial on the machine’s thread path controls top thread tension; it’s called a sewing machine tension dial. Discover all sewing machine parts in our exhaustive guide. 

Dial’s sewing machine tension numbers run from 0 to 9, with 4.5 as the default position for regular straight-stitch sewing, suitable for most sewing fabric types. 

Sewing machine tension
Image source: Palm Gear

The thread should sit correctly between the tension discs when threading your machine. Otherwise, your sewing machine won’t sew properly. 

To ensure you place the thread correctly in the tension discs, after putting the spool on the machine, pull out 18 inches of thread (holding it still in your non-threading hand) and “snap” the thread into the tension discs.

When your presser foot is up, the tension discs are open. Hence, there is no tension on the top thread. 

Were you ever wondering why you get so many loops when trying to sew with the presser foot up? You have the answer. Yet, having the foot up as you thread the machine helps to get the thread between the discs. Remember to thread the machine with a raised foot as most tension discs close when the presser foot is down.

The collective work of 

    • thread guides, 
    • tension discs, 
    • tension regulators, and 
    • bobbin-case springs

provides the correct tension for your sewing machine. (by PalmGear

The flat bobbin-case springs pressure on the thread the moment it moves out from the case. The tiny screw at the back of the spring regulates the pressure—Homey Sew illustrates the process. 

Finding the tension screw in machines with a built-in bobbin case and a drop-in bobbin is challenging. Before we explain the entire process thoroughly, to tell you briefly, to improve the resistance, hit the screw with a small screwdriver clockwise (to adjust it to a higher number) or counterclockwise (to adjust it to a lower number). 

Do it very slowly and avoid turning the screw beyond quarter-turns. 

Have a look at the sewing machine tension chart below to grasp what’s going on inside the fabric you’re working on. 

Adjusting thread tension
Image source: CTPub

A cool part of the sewing machine tension concept is that it’s all about harmony. 

To achieve a correctly formed stitch, the machine needs a top and bottom thread to collaborate, interlinking precisely in the middle of the fabric. 

Any imbalance will cause one of them to pull the other through to the other side of the fabric, causing a poor quality stitch—the one that isn’t aesthetically pleasing or just doesn’t hold.

Stitches banner
Image source: Contrado

How to set tension on a sewing machine?

We know what a sewing machine tension is; let’s see how to adjust the tension on a Singer sewing machine (and any other brand). 

Steve from “Sewing with Steve” in the Bag Buff splits the entire story into two videos: 

    1. “How To Adjust Bottom Tension on a Sewing Machine,”

      2. “How To Adjust Top Tension on a Sewing Machine”

Still not there? Let’s tackle it below. 

Sewing machine tension numbers
Image source: Homey Sew

They say that math is the queen of science, so let’s see what numbers tell us and how to use them in the sewing machine tension section.  

It’s not a problem to count from zero to nine, yet, adjusting the tension on a Singer sewing machine using these innocent numbers is a little more challenging. 

Jenifer Wiese from Workroom Social explains tension control sewing machine numbers neatly: 

    1. the lower number means that the threat is loose, and
    2. the higher number, going up to nine, means that the thread is tight;

Take a minute to listen to the author on the Howcast YouTube channel:

We must thread all sewing machine tension guides before stitching—properly and along their accurate paths.

Every thread guide shows little resistance to the thread, adding tension to the machine’s discs. As a result, we achieve a balanced tension.

Remember that, as stated by Sewing is Awesome, the thread tension changes depending on 

    • what you are sewing, 
    • the thickness of the fabric, and 
    • what kind of thread you are using;

Therefore, you are not supposed to sew always at the 4,5 setting, even though it’s so universal. 

Every sewing machine has its unique tension setting, independent from the numbers, which are generally equal on every sewing device. 

Work on becoming comfortable setting tension on Singer sewing machine, Kenmore, Bernina, or Janome sewing machine

If things don’t go as expected, move the dial-up or down one or two numbers using a spare piece of fabric for test sewing. Keep in mind that the scrap you use for check must be the same fabric you will use in your project. 

Here’s another hint: If you run your fingers along the stitch’s top and bottom and feel it’s smooth, the tension number you’re using is correct. 

You’ll get better and better at adjusting tension with time!

Take a look at the thread tension sewing machine tension chart below.

Sewing machine tension guide
Image source: Blog Treasurie

Let’s get down to business and adjust any irregularities showing up in the tension department, shall we?

Tension adjustment comes in two different types:

    • Basic adjustment—used for regular sewing projects and usually performed by professional service (however, you can also do it easily by yourself, so keep reading),
    • Temporary adjustment—the type of adjustment a sewer applies every time they need to change a sewing machine’s threads, etc.

(by Homey Sew)

To adjust tension within the first, basic type of adjustment, pick a complementary thread color based on the size, brand, and type of material that you plan to use most often. Then, fill the spindle with it. 

Place a new needle in your machine, which must be the same size as the thread you use in your day-to-day sewing, set your machine at an average speed, and thread the machine. It’s a good idea to use thread guides, so you don’t have to thread the needle eye the traditional way. 

When it comes to the stitch length, go for any size you wish to use regularly; a typical length is 2 mm. 

Set the upper-tension regulator at an average range, i.e., 4 or 5. 

Now you can take a lightweight cotton cloth and test seam sewing the two layers together. 

Investigate carefully the stitches that come out; you can even do it with a magnifying glass!

Eliminate any flaws on the stitches by adjusting tension until it’s just right.

Adjust the bobbin spring; tighten it if it’s wobbly. 

If the bobbin thread located on the upper layer has an underlayer, loosen the bobbin spring. 

Test the seam again. Repeat as many times as necessary.

Understanding thread tension on sewing machine
Image source: Threads Magazine

To put it shortly:

    • Loops at the back of the fabric mean the top thread tension is too loose. To increase tension, select a higher number on the sewing machine tension dial.
    • Loops on top of the fabric mean the top thread tension is too tight. To decrease tension select a lower number on the sewing machine tension dial.

For the record: greater pressure is needed when you work on thicker threads. 

On the other hand, loosening the machine’s top tension is ideal if you’re topstitching.

Now, your goal is a perfect balance, so we’re working on setting the machine so it forms uniform stitches on both sides of the fabric.

Observe if both threads are flowing in the same amount at a given time. You may want to test it by running the thread using tension discs, thread guides, bobbin-case springs, tension regulators, and other tension devices. 

Some sewing machines contain a small-holed bobbin-case finger. This feature lets you improve the tension by merely feeding the bobbin thread through it. 

With improved tension comes a more defined stitch. Think about what it does to your embroidery, satin-stitching, and topstitching efforts. And it all comes without even touching tension settings!

A tension assembly is a “team” composed of a tension regulator and tension discs. 

      -tension disc squeezes the thread the moment it passes through it,

      -tension regulator manages the level of pressure that occurs on tensions discs; 

Older sewing machines have barely two tension discs, regulated by a knob or a screw. 

Advanced sewing machines have three discs and get managed by a keypad or a dial on the front of our device. These discs work by controlling two threads at the same time. 

The way tension regulators work is simple. To set the tension higher, turn the regulator clockwise, so the tension discs get closer, increasing pressure on the discs. 

Turning the regulator counterclockwise moves the discs apart, giving the tension discs less pressure. 

Keep in mind that sewing using a thicker thread increases pressure on the discs. A thicker thread could mess up your sewing process if there were no options for resetting. Luckily, you can manually adjust the tension dial to match the machine setting. 

More sophisticated sewing machines with automatic upper-tension adjustments self-adjust so such issues don’t ‌occur. 

Fixing tension on sewing machine
Image source: Sewing Machines Plus

Sewing machine tension problems

Handling sewing machine tension issues is a piece of cake if only you are aware of the mechanisms that rule these dynamics. 

Several factors can throw off thread tension—notices Threads Magazine.

Before handling sewing machine thread tension by adjusting the sewing machine tension settings, consider the following issues:

    • Is the sewing machine needle bent, or does it have a burr on the tip?
    • Is the needle the correct size for the fabric?
    • Is the machine threaded correctly? 

Anika from Made to Sew explains “How To: Deal & Understand Tension Problems (Sewing for Beginners)” with her super clear video below:

Are you a beginner? Have a look at our sewing machine for beginners guide. We also covered the handheld sewing machine category for your best experience. 

Sewing machine tension troubleshooting is a large part of the sewing machine tension topic. In fact, it’s mostly sewing tension problems that make us reflect on sewing machine tension in the first place. 

Sewing machine tension issues
Image source: GoldStar Tool

Based on the findings by Blog Treasurie, there are ten factors worth considering when sewing machine tension gives us any problems:

Factor Description
Needles (read here about sewing machine needles) A bent or blunt needle can cause your tension to go out, so replace it if necessary. Also, check it is inserted correctly into the needle holder (the flat part of the needle should be at the back). Factors such as if needles match the type and weight of your fabric also matter here. For instance, you will need a needle in a heavy gauge for sewing leather. (discover leather sewing machine)
Correctly threaded (study our complete guide on sewing machine thread)

To ensure the proper sewing machine tension, thread the sewing machine correctly. If in doubt, simply rethread both the top thread and bobbin (as if it was so simple, huh?). Control if the bobbin is wound evenly with no loops and the thread went through the tension disks correctly.

Dirt Notice any fluff caught in the wheels, throat plate, bobbin, or even…in the needle’s eye. That’s not a problem—a small stiff paintbrush can sweep your machine clean and get your sewing machine tension back to normal. 
Correctly set dials

Sometimes, a sewing machine tension dial changes its settings by accident while you’re sewing or reaching out for your cup of tea. Children love to play with them as well (maybe it’s time for a kids sewing machine if this is the case). 

Check if all dials are set correctly. At this point, you may wonder, “what tension should my sewing machine be on?”. Consider that most sewing projects have the tension dial set somewhere in the middle, around 4,5. Control your sewing machine manual for instructions.

The Spruce Crafts observed that sewers and quilters are hesitant to adjust sewing machine tension when stitches aren’t quite right.

They are scared that the adjustments could create even more issues. 

Don’t think twice! Adjustments are often necessary or can at least lead to much better performance, so ‌follow our guide and get your DIY outfits to the next level with minor effort.

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Getting back to Blog Treasurie tips, what else can ‌disrupt Janome, Kenmore, or Singer sewing machine tension?

Factor Description
Thread quality  Several sewing machine brands and thread brands have been on the market for over a hundred years! Invest in a reputable brand and always choose quality first. Not only can cheap brands be uneven and break easily, but they can also cause sewing machine tension issues. Using better quality threads gives your machine a better experience, and it will pay you back!  
Matching thread We mentioned that the sewing machine needle should match the sewing fabric to ensure smooth sewing and resolve sewing machine tension issues. With thread, matching boils down to both the top thread and bobbin being the same brand, quality, and weight. If they are mismatched, expect tension problems. Luckily, different threads’ colors are not an issue here.
Top thread caught If you were wondering how to fix the tension on a Singer sewing machine or any other model of sewing machine brands, ‌check if the top thread is not caught around the base of the spool. It can cause the top tension to become too tight and ruin your sewing machine tension-balance efforts. Also, check for any knots or tangles in the thread.
Machine damage (let’s handle sewing machine repair together)

When there’s more considerable damage, we won’t have to tell you where to look for it on your machine. Yet, with more minor issues, you may have to look closer. 

Check if the throat plate is clean and has no unwanted nicks or damage. We never recommend sewing over pins and needles, as breaking them can cause nicks in the throat plate. These nicks can, in turn, snag the bobbin thread. Contact a technician to buff the nicks smooth or buy a new plate (and never sew over pins and needles again!).

Read about sewing machine table for the most comfortable and uninterrupted sewing experience.

According to Blog Treasurie, at least two more factors can show you how to fix the tension on a sewing machine:

    1. Bobbin winding—control if the bobbin hasn’t got snags and if it’s wound evenly and not too tight. 
    2. Bobbin case—verify if the bobbin is inserted correctly. Some machines have an adjustment screw on the bobbin case to act on any potential inconsistencies. You can always check your sewing machine manual and adjust the bobbin case accordingly.

Get familiar with “A Guidebook on Bobbin Winding” on Fashinza.

A guide on bobbin winding
Image source: Fashinza

As stated by the authors of the Homey Sew, factors that affect stitch balance are:

    1. Fabric—some densely-woven fabrics (think duck cloth, batiks, and denim) make the top thread more exposed to friction, while loosely-woven fabrics (e.g., knits and quilting cotton) lets the thread get through the material’s fibers with no trouble thanks to the lesser friction. During stitching, the latter have lesser tension on the threads. 
    2. Batting—increases the amount of strain present in the top thread. Batting can double the stress level on the threads with every stitch formation, depending on density and loft. 
    3. Bobbin thread—filament polyester threads are smooth. Cotton threads need to be set at a higher tension. Sewers often prefer threads that call for less tension when patching or repairing quilts. Smooth bobbin threads are preferred for sewing metallic and other decorative threads. 
    4. Top thread—its material and thickness influence stitch balance and quality. For instance, the polyester thread needs a more loosened tension dial for a seamlessly even stitch on thick materials. 

So, there are circumstances when you’re supposed to loosen the tension numbers to hit the appropriate stitches. 

Also, there’s nothing wrong with mixing various types of threads. You can achieve seamless and balanced stitches, but you need to be aware of the proper technique of tension adjustments. 

If you aren’t familiar with any of these terms, read how to sew and how does a sewing machine work

How to adjust the tension on your sewing machine
Image source: Sewing Is Awesome

Say you’ve covered all these potentially influential factors, but your sewing machine is still erratic and unbalanced in the tension department.

One option left is to try sewing a different type of sewing fabric

If this changes the situation, your sewing device probably isn’t that suitable for your projects, and you might want to look for a different best sewing machine

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