How To Fix Sewing Machine Tension Knob?

Proper sewing machine tension is necessary because it guarantees that the stitching is even and looks the same across all sides.

It ensures that the thread moves smoothly when you stitch (tight tension might not let the thread move). It is what maintains equality between the bottom and top stitches.

Or, to put it another way, this is what maintains symmetry between the front and the back stitches. It’s possible that the tension is off on the upper or the lower side and your back and the top stitches are not similar.

Both the lower tensions and the upper tensions must cooperate for a flawless stitching job to be done.

Tension control on sewing machines is handled by mechanisms that control the needle threads and the bobbin thread individually, applying different levels of tension (or strength) to the threads they control to make a strong, balanced stitch.

The tension of a sewing machine can be adjusted or relaxed to impact the needle thread, bobbin thread, or both.

How To Fix Sewing Machine Tension Knob?

There are a few indicators that you can observe if the sewing machine tension is off. So, let’s discuss the three key indicators briefly.

1. You are Observing Some Unbalanced Stitches

When sewing patchwork pieces with each other or machine quilting through the quilt’s cover, batting, and backing, machine threads should look the same across all sides of the seam. Stitches that are balanced will be uniformly spaced on either side of the seams, with threads that sit smoothly on the cloth.

  • The little knot generated across stitches (at each dip between them) should be hidden behind the layers.
  • If both threads readily rip out of the seam when tugged, you have a sewing machine tension issue.

2. Bobbin Thread is Visible on the Upper Side of The Fabric

The presence of bobbin thread on top of the item you’re stitching might indicate one of two things:

  • The tension that regulates the thread passing through the needle is far too strong, causing the bobbin thread to rise to the surface.
  • It is possible for the tension of the needle thread to grab hold because the tension that regulates the thread emerging from the bobbin is insufficient.

3. You Can See the Needle Thread On the Bottom of the Fabric

If you notice needle thread on the lower side of your patch or quilt, it might imply one of two things:

  • The tension controlling the thread flowing out of the bobbin is too much, dragging the needle thread to the underside.
  • The tension controlling the thread passing through the needle is insufficient.

Things that You Must Double-Check

Before you touch the dial, please check the following to ensure a smooth sewing experience and to avoid any hurdles due to knob tension issues.

  1. Firstly, you need to make sure that the hook region has been oiled properly. Also, ensure that the right presser foot for the procedure and cloth is connected.
  2. Check that the machine is properly threaded. Use the thread guides and put down the presser foot, so the thread does not completely slip between the tension discs. Make sure that the thread is not winding from the spool and is not getting stuck on the spool’s slash. Moreover, if you are going for a bobbin for the spool, make sure it is inserted correctly because it can easily hinder the thread and can stop it from flowing properly.
  3. Lint as well as thread end that get caught between the discs, beneath the throat plate, and around the bobbin create resistance and hinder thread movement. Wipe the tension discs using a light, clean cloth, and look for thread remnants and lint in the bobbin region.
  4. Abrasive or scratched parts on the needle heads, thread guides, the discs, the lever, the throat plate, the presser foot, and in the bobbin region, as well as curved needles and bobbins, can all create issues. If you knock a metal bobbin off onto a hard surface, don’t use it, even when it appears to be in good condition; even little damage might alter tension. By breaking off the thread near to the casing before extracting the bobbin, you can avoid damaging the bobbin-tension spring.
  5. Mixing sizes and kinds of threads on the top and in bobbin might cause basic tension controls to be thrown off. A needle too big or too little for the choosing thread can also throw off the balance of your stitches since the hole size increases or decreases the overall top tension. In case you’re finding puckers on lightweight materials, consider switching to a straight-stitch foot with a needle plate and shortening the length of the stitch to 1.75 mm (15 sts/in.) before reaching for the tension dial.

How to Quickly Fix the Tension Knob Issue?

There are two ways to do this and none of them are complex. So, let’s discuss each of the ways without further ado!

Option 1: Go for the Basic Adjustment

These are considered basic adjustments for day-to-day or regular sewing. It can be seen as the general tension adjustment, which can be applied to a lot of different stitching methods, fabrics, and designs. This is the adjustment that a repair person makes when asked for a tension repair.

For this, choose color combinations in the thread type, thread size, and thread material that you use the most. Choose one color and place it in the bobbin. Set the machine at a normal speed to avoid straining the thread.

Thread the sewing machine following all of the thread guides given on the machine, but make sure that the eye is not attached to the bobbin-case finger if you do have that option on your sewing machine.

  • Select the stitch length which you want to use the most (suggested length is 2 mm or 12 stitches per inch).
  • Bring the upper-tension regulator to the center of the given range (usually a 4 or a 5 on most machines), then make a trial stitch on two sheets of muslin, then inspect the stitches.
  • Use a magnifying glass if required.
  • If you find that the tension isn’t just right, adjust the bobbin spring to become tighter if the bobbin thread is visible on the top layer or adjust it to be looser in case the needle thread is visible on the bottom layer.
  • Repeat the trial seam and evaluate the stitches until the stitch looks symmetrical, which indicates that it has been balanced.

Once this is done, keep a tension record in your machine manual, noting the thread type, thickness, type, and perhaps even the number on the regulator that resulted in the required stitch. Then, take a picture of the bobbin screw position for reference in case you ever need to document a variation in bobbin parameters for different threads.

Option 2: Consider a Temporary Adjustment

The second type of adjustment is the temporary adjustment, which is done when the thread types, thread sizes, thread material, fabric styles, fabric types, or stitching methods are changed.

  • For a temporary adjustment, choose the threads and fill them in both the needle and the bobbins.
  • Stitch a test seam on the cloth you intend to sew, inspect the stitches, and try to strike a balance with just the upper-tension regulator.
  • When switching from one thread to the other, thread the sewing machine beforehand and test the setup to determine if things work out with just a temporary adjustment or not.
  • If it doesn’t work, take out the second bobbin case and begin turning the screw in quarter length to open or close it according to your test stitch.

Even if you go for a softer thread than you would typically use for both the needle and the bobbin, the tensions won’t usually go off. Mostly, this is all you will have to do to prevent lightweight fabrics from puckering, so no alteration may be needed.

Going for a much heavier thread on the top and the bottom will raise tensions in both, and you’ll most likely have to set a lower tension to handle thicker fabrics.

Here’s the Bottom Line!

The tension in your sewing machine is as important as the design you are making or the fabric that you choose. If the tension is off, the entire pattern will look unappealing and will probably come apart very quickly. Making sure that the tension is well and working should be the utmost priority before beginning any stitching session.



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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