Sewing Machine Thread Tension Adjustment Tips
I LOVE to sew but there is ONE thing that has been a constant challenge for me; Sewing Machine Thread Tension Adjustment! I could never remember which numbers on the tension knob I should choose for the adjustment I need to make. LUCKILY, I do know what balanced stitches should look like and now understand which numbers to choose when tension needs correcting. I will help you with SIMPLE explanations and photos to better understand tension and where the tension numbers should be.
What tension number should my sewing machine be on?
Sewing Machine Tension Knob
You can see in the image below that this Sewing Machine Tension Knob is at the top of this machine. Your machine could have the tension dial in about the same place OR possibly on the side of the machine.
I have been making some samples using muslin and stitching at different tensions so you can see how the thread/fabric looks when adjusting the tension number on my machine. My attempt at trying to explain what I see in each of my samples will be directly below each image.
I encourage you to make samples as I have done, especially using fabric samples from the project you will be sewing. As you know, Sewing is a ‘hands on’ experience and you will be able to better decide on a correct tension when you can see and feel the fabric and thread.
What tension number should my sewing machine be on?
Ultimately, the tension number your machine will be is dependent on the type/weight of fabric you are using. The average starting point for tension number would be a “4” or “4.5”. Some machines may vary slightly in the average tension starting area.
My Baby Lock machine has the starting tension area of #3-4-5.
My Elna machine has colored zones and ‘THE WHITE ZONE is most commonly used, medium, closely-woven and heavy fabrics; 4-5-6.
Read your machine manual to get familiar with your starting tension # area.
I’ve always been able to correct the tension with the steps shown below. If your machine gets to the point where you just can’t figure out your tension- it may be time for a sewing machine tune-up and cleaning BEFORE adjusting the bobbin tension!
Correct Thread Tension
The upper thread and the lower thread should cross near the center of the fabric. You should only see the top thread on the right side of the fabric and the bobbin thread on the wrong/back side of the fabric. The following images are samples of a straight stitch on cotton muslin fabric. I used a top blue thread and a pink bobbin thread so you can see what the thread does as the tension number changes.
This cotton muslin, in the image above– right side of fabric, could use the tension number of 3 or 4. The tension 5 setting starts to pucker the fabric just a little bit.
In the image above, this is the wrong/back side of tension numbers #4, #5 and #6. You may be able to see that tension #5 makes the fabric pucker just a bit.
Upper Thread Too Tight
If the bobbin thread is visible on the right side of the fabric, the upper thread tension is TOO tight. You will turn the tension dial to a lower number to loosen the upper thread.
In the image above–right side of fabric, the pink bobbin thread is visible between each blue stitch; not so much on Tension#6 sample but definitely on samples #7, #8 and #9 (Hard to see unless you can zoom in on image.) Also, notice that the higher the tension, the more the fabric is pulled and puckers. You can also see the shadows, looking to the right side of the fabric on the blue mat, the shadows get gradually larger.
In the image just above–wrong side of fabric, you can also see on samples of tension #7, #8 and #9 how the fabric is puckering from the thread being pulled too tight. The higher the tension dial number, the more puckering there is. In this case, you’ll want to decrease the tension number.
Upper Thread Too Loose
If you can see the upper thread on the wrong side of the fabric, the upper thread is too loose. You will turn the tension dial to a higher number to tighten the upper thread.
In the image above, the top thread looks OK but if you could actually see my samples, the thread sits loose on top of the fabric.
In the image above which is the wrong side of the fabric, you can see that the top blue thread is showing and this tells you that the tension is TOO loose. You need to turn the dial to a higher tension number to increase the tension.
Bobbin Checklist Tips to check the will help achieve proper thread tension
- Make sure your bobbin thread is wound correctly and set into your machine the proper direction.
- Use the correct bobbin for your machine.
- Follow guide arrows for bobbin thread while threading your machine.
Check out these Basic Steps for Winding a Bobbin– scroll about half way into this article.
Thread Tension still not cooperating after these adjustments?
IF upper thread and/or bobbin thread are off in the slightest, as far as threading is concerned, the correct tension will be hard to achieve. Try re-threading your machine. You should also check to make sure you have the proper needle size for the fabric you are sewing on. Maybe you need to replace your current needle with a new one; sometimes needles could have the slightest bend or imperfection.
One thing I have NEVER done on any of my machines is adjust the bobbin tension.
Your machine may have a removable silver insert to add bobbin in and then put insert into your machine, or you may have a place where you just set the bobbin. Newer machines have the dedicated ‘bobbin space’ which makes it easy to slip the bobbin into its place.
I’m not sure of the correct bobbin part name but I do know it can be removed to clean your machine and also has a TINY screw to adjust bobbin tension. I’ve even looked in my manual and found no mention of a proper name for the bobbin holder 😂 If you know, send me an email!
As I mentioned, Lower Bobbin tension adjustment is NOT recommended especially if you’ve never adjusted it before. If you have attempted to adjust the BOBBIN tension, you may need to re-adjust.
I really hope now that you understand how to change your sewing machine thread tension more than you did before! If your tension is too loose, turn tension dial to a larger number. If your tension is too tight, turn tension dial to a lower number.
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Thanks for Visiting- Happy SIMPLE Sewing to you! If you have any questions, send Amy an email at amy@amyssewingstudio.com