How to adjust tension - Sewing Machines

Tension is most often adjusted at the top tension dial. Only in extreme cases where the top tension does not make the needed adjustments would you need to adjust the bobbin tension. Also, bobbin tension is very sensitive and can easily throw your machine into a tizzy.

Basically, sewing machine tension is simply a tug-of-war between the top and bobbin thread. When they are equally matched, the threads will meet in the middle of the fabric. This is the optimum tension for most sewing. If the bobbin thread is coming up to the top of the fabric, the top tension is too tight--loosen it. If the top thread is going to the underside of the fabric, the top tension needs to be tightened. The higher the number on the dial, the tighter the tension.

FWIW, tension is static. It is not one of those, set it and leave it forever deals. Whenever the fabric, needle, thread are changed, there's a good chance the tension will need to be tweaked.

Understanding Thread Tension Threads

Find your manual as it identifies specific parts related to adjusting tension. Here are some pictures of problematic stitches and suggestions on fixing sewing machine tension:

How to Adjust Sewing Machine Tension on Craftsy

https://www.wikihow.com/Adjust-the-Tension-on-a-Sewing-Machine

Sometimes you adjust something other than the tension:

Adjusting Sewing Machine Tension to Prevent Problems

How to Achieve Ideal Sewing Machine Thread Tension Threads