Adjusting the Lower and Upper Thread Tension

Adjust upper and lower thread tension.

  • Start with a new needle in your machine (even if the needle still looks good, do it anyway).
  • Always use the same sewing thread at the top and bottom; the better the thread, the nicer the stitch.

Pay attention!
If the tension on the right side of the fabric isn't good, than most of the time the problem is the bobbin (bobbin thread tension).

If the tension on the wrong side of the fabric isn't right, than the problem is most of the time the upper thread: not threaded correctly (Upper thread tension).

Adjust and check upper thread.
Raise the presser foot, thread the upper thread past the tension plates (green arrows),
then lower the presser foot and check that the thread is clamping properly.

If the thread does not clamp properly, there is dirt or thread residue between the tension plates.
This can be removed by "flossing" well between the tension plates.
Then try again.

Adjust and check the bobbin thread.
There are 2 types of hooks, see the photos

1 The CB hook

Remove the bobbin case and bobbin and insert the bobbin: 

  • Pull the thread through the slot while keeping the bobbin fixed.
  • Pull the thread and you can see the bobbin turning clockwise (as shown in the picture).

You can test the tension by hanging bobbin and bobbin case, keeping the thread between your
fingers. Move your hand up and down slowly the bobbin and bobbin case should drop about only 1 cm.

If this is not the case, loosen or tighten the small screw a bit.

2 The horizontal hook

Take out the bobbin and insert the bobbin as shown in the picture.
Some hooks may look slightly different, but this doesn't matter.

Pull the thread well through the tension groove; you will feel the thread getting tighter.
You can check this by pulling on the end of the thread. If the bobbin is installed correctly,
then the bobbin should rotate smoothly without wobbling.

Now we can start testing:

  • Use normal fabric and always sew at least 2 layers of fabric, one on top of the other.
  • First start with the straight stitch with a stitch length of 2.5 to 3.
  • Then you can try the zigzag stitch (the width in 3 to 4 and the length in 2).
  • Normally the stitch should be perfect now.


Performing periodic maintenance on your sewing machine is particularly important.
A well-maintained machine will likely run better and prevent annoying, time consuming, and costly problems later.

You can easily do this yourself with our free maintenance tips.
View our maintenance films here!

Order your maintenance kit here including needles, oil, brush, screwdriver, etc.