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

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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 generally 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

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

      Hi Tamara. Yes! Most of our projects and patterns are downloads, so you can save them to your computer to print. Otherwise you can always print web pages directly from your internet browser. Thanks! Hallie NSC Video Membership

  1. Marcy Taitz
    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.

    • Customer Service
      Customer Service

      Hello Hilde!

      I’d love to help! Are you looking for 15 or 15J size bobbins?


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  2. laverne Currie
    laverne Currie

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

    • Customer Service
      Customer Service


      I would recommend using a medium-weight Universalor Microtex (Sharps) needle. This will help ensure you easily pierce through this slightly heavier fabric.