Superior Education

Fix Broken Bobbin Threads

  • Bobbin Tension
  • Bobbin Thread

Why is my bobbin thread breaking?

Q. I have a gross of prewound bobbins (if it helps, the sticker on the box says "Amiral L24") and it works just right in my Pfaff 2140/70. I mentioned to a friend that I would like a thread that isn't as linty as the admiral bobbins and was recommended to use your MasterPiece bobbins. I'm using the L-style prewounds and am experiencing some problems. I seem to stitch out for about six inches or so and then the bobbin thread breaks away. I turned the bobbin upside down to have the thread unwind in the opposite way and the results were the same, stitch for a bit and then the bobbin thread breaks. I thought it could be my needle, so I changed my needle but am still experiencing thread breaks. Any suggestions to help me out would be really appreciated.


Super Bobs Cotton prewound bobbins
Super Bobs Cotton prewound bobbins
Bobbin case
Metal bobbin case

A. It sounds like you've read through our Troubleshooting Guide and have made tried a new needle. In a well-maintained machine, you should not be experiencing thread breakage at a frequent rate and thread breaking every six inches makes for a frustrating experience. Let's try loosening the bobbin tension to see if that will solve the thread from breaking.

With a permanent marker, mark a dot on the bobbin case where the large screw is currently pointing to. This dot will provide you with a benchmark that you can return to if needed. Loosen the bobbin tension by turning the bobbin tension screw in small increments, a quarter turn at a time. Turn to the left (counter clockwise) to decrease the amount of tension placed on the thread as it leaves the bobbin case.
This should solve the problem you're experiencing. Many home sewing machines are factory set to have a very strong polyester thread in the bobbin and therefore need to be adjusted when using a fine cotton thread, like MasterPiece.

Customer response:
Thanks so much for your information! A simple quarter turn counter clockwise and my bobbin thread didn't break at all! I love that there's hardly any lint with your cotton thread too. Thanks again.

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