Class 15 vs. 15J Bobbins: Are They Interchangeable?

Ask an Expert Banner NSC
NSC Question
Are all size 15 bobbins interchangeable? Metal and plastic? 15J vs. plain 15? My machine manual does not have the bobbin size anywhere. I watched two different instructional videos on that model—one said 15J and the other said 15. I called the company and also got an ambiguous answer. 15J came with the machine. I’ve measured everything I can measure, and I can’t see any difference between them.

Submitted by Patricia


NSC Answer
Class 15 bobbins and size 15J bobbins are not always interchangeable as the 15J is slightly smaller. However, one of my personal machines uses class 15 bobbins and I accidentally purchased 15J bobbins for it. The only place this was an issue on my machine was on the bobbin winder—the class 15 bobbin wound just fine, but the 15J just spun in place. The 15J that I purchased were pre-wound and using the bobbin straight from the package did not affect my sewing; however, I just can’t rewind them.

This being said, if 15J came with your machine, that is the type you should use.

Hope this helps!


Related Video: Bobbin Sizes: Understanding the Sizes of Bobbins

You might also be interested in: :

How to Wind a Bobbin Correctly Every Time
How to Adjust a Rotary Bobbin on Your Sewing Machine
Bobbin Work
Proper Bobbin Use
What Size Bobbins Do I Need?
Bobbin Storage & Transfer
Understanding the Benefits of Bobbin Winders  

Do you have a sewing question you’d like answered by an expert? Email your question to or reach out to us on Facebook.


Please note: questions may be edited for clarity and relevance.  

Share tips, start a discussion or ask one of our experts or other students a question.

Make a comment:
500 characters remaining

7 Responses to “Class 15 vs. 15J Bobbins: Are They Interchangeable?”

  1. Wendy Maisonneuve

    Where Can I get an Owner Manual for my Euro-Pro 1260 DX Sewing Machine? Thank You.

  2. Diana Neill

    I own two machines--one calls for 15 and the other calls for 15J. Although they both seemed to work interchangeably while I used them, I ended up having to replace my bobbin case in the one that uses 15. So I highly recommend finding out the correct bobbin and if it can work interchangeably with others.

  3. June

    Can you please tell me how to work out the length of cord I will need to gather a frill on a women skirt. Ie Is it twice the length of the hem of the skirt.

  4. laverne Currie

    I have a Bernina 480 machine. What size needle to used for brocade lace fabric?

  5. Hilde zahm

    Joann’s had bobbins size 4 or 6. I can not find any info can you help me. Thanks

  6. Marcy Taitz

    I inadvertently used a Singer class 15 bobbin in my Brother machine which says to use sa156 (or 15j which is the same) and it worked fine. I have a lot of the class 15 from my previous machine. Is there any problem if I use them? Thanks for any help on this.

  7. Tamara Anderson

    Can I print the instructions for the projects