Machine Tension

Your Sewing Machine Tension is controlled in two places, the top thread with tension discs as the thread feeds into the sewing machine and on the bobbin casing with a screw or other tension mechanism. When the tension in both locations is set for the thread, what you are sewing on and the top and bobbin threads, the result is a flat stitch on the top and bottom fabric, with no top thread showing on the bottom and no bottom thread showing on top. Machine tension is factory set using the same thread in the top and bobbin. In all likelihood however, you'll need to make adjustments based on threads you use, the types of fabric you're sewing, if you're machine quilting, and even if you're just piecing a quilt. Here are some things to try before you start touching the dials and messing with the bobbin when your machine stitch isn't right:

  1. Rethread your top thread on the machine 
  2. Rethread your bobbin
  3. Clean your bobbin and tension areas checking for lint build up
  4. Insert a new needle
  5. Check the needle you are using to make sure it is the right one for the sewing you are doing
  6. Use a good quality thread -on top and in the bobbin.

If these things don't fix your problem it's time to get your manual out to identify your problem. Most Machine Tension problems involve tension as the tread comes into the machine, so start there before you start working on your bobbin! Your sewing machine manual will guide you through the process of fixing your machine tension.  We have also provided information in the Reference Guides in Learn. Check out our lessons on the Thread Tug of War from Superior Threads and How to get Perfect Stitches from We All Sew.

Benefits of Proper Machine Tension

  • Proper Machine Tension creates a quality stitch with no bobbin thread on top, and no top thread on the bottom.
  • The seam will be secure and the threads will not be visible when the seam is open.

Tools and Supplies for Machine Tension

When checking or adjusting your Machine Tension, you'll need:

  • Sewing Machine Manual to ensure thread is positioned on top correctly and can freely feed.
  • Sewing Machine Needles appropriate for the project.
  • Quality Top and Bottom thread for the project.
What I Wish I Knew When I Started adjusting Machine Tension

A second bobbin case will allow you to keep the primary bobbin case set at the factory settings. Use the secondary bobbin case for anything that requires bobbin adjustment such as machine quilting or sewing on heavy fabric.

If a second bobbin case is not an option, use an indelible ink marker and draw a line on the bobbin case through the slot in the adjustment screw so it shows on both sides at the setting that you use most frequently. Then if you need to make MACHINE TENSION adjustments, you can easily return the adjustment screw to the position that works the best for the majority of your sewing.

Machine Tension Resources