Why is My Thread Breaking? Reason #5: The Needle is Too Small

I'm often asked in my free-motion quilting classes "What is the right size needle for quilting?"

In fact, this is sort of the wrong question, because the needle size to use is not so much determined by what kindof sewing you are doing (piecing, quilting, etc.) it is determined by the size of thread you are using and the size of thread is determined by the weight of fabric you are using.

FIrst, let's understand the relationship between the needle and the thread.

Take a look at the needle at the far left size of the chart below and find the arrow pointing to the "front groove."  The purpose of the front groove is to let the thread push back into it while the needle is going through the bobbin race. When the thread is pushed into the groove it is protected from rubbing against the parts of the bobbin race.

The thread has to be able to fit into that groove.  If the thread is too large for the groove, it will bulge out and rub against the bobbin race. Rubbing can fray the thread and cause it to break.

Threads that are typically used for garment sewing and piecing are 50-weight. Some 50-weight threads are 2-ply (50/2), meaning they twist together 2 strands, and some are 3-ply (50/3), which twist together 3 strands.  Superior's Masterpiece and Aurifil's 50-weight are examples of 2-ply threads. Gutermann and Mettler are 3-ply so they are heavier. (Personally, I prefer a thinner thread for piecing, as it lets the seams and corners lie flatter.)

For "average" quilting, a 50-weight or 40-weight thread is a good choice. I really like Superior's 40-weight trilobal polyester that's sold under the names Fantastico and Magnifico; Glide is another brand of 40-weight trilobal polyester. Superior's 40-weight cotton is King Tut.

Keep in mind that the size of thread is thicker as the number gets smaller.  Needles get larger as the number gets larger.

So, going back to the question about what needle to use for quilting, the answer depends on the fabric, the thread, and the size of quilting. 

On regular cotton fabrics, with a 50/2 thread and quilting of average size and density, use an 80/12 needle. 50/3 thread may work better with a 90/14 needle. 

On regular cotton, but with very small quilting, step up to a 100-weight thread, either silk (such as Superior's Kimono) or polyester (Wonderfil's Invisafil) and use it with a 70/10 needle. This would also be a good choice if you are quilting silk.

If you have jeans in your quilt, you might want to quilt with a topstitching thread that matches the topstitching thread in the jeans -- this will be around a size 12 thread and may require a 110/18 or 120/20 needle.

You may need to experiment a bit to find which combination of thread and needle is right for your particular project, but these recommendations are a good place to start.

(The needle sizes I've given here are for a domestic machine. Longarm sizes are different. To learn more about longarm needles, check out this article from APQS.)

Heavier fabrics, such as canvas or wool for example, require heavier thread, which will require a larger needle. Lighter fabrics require finer thread, which will require a smaller needle. Click here for an article from Sew Jersey that provides a detailed list of fabrics with recommended needles.

Superior Threads provides a needle recommendation for each of their threads. They also have quite a few educational articles about thread and needles (click here to explore them).