Choosing the right polyester sewing thread sizes is not simply about selecting a thicker or thinner thread. For garment manufacturers, sewing factories and thread buyers, choosing the wrong thread size can lead to frequent thread breakage, skipped stitches, poor seam appearance and unnecessary production downtime.
Common polyester sewing thread sizes such as 20/2, 20/3, 40/2, 40/3, 50/2 and 60/2 are designed for different fabrics and sewing applications. Choosing the correct thread count can help improve sewing performance, seam quality and production efficiency.
So, what do these polyester sewing thread sizes actually mean, and how can you choose the right one for your production? In this guide, we will explain the differences and help you avoid some of the most common sewing thread problems.
Why Choosing the Correct Sewing Thread Size
Choosing the wrong thread size can cause more than poor-looking stitches. In high-speed garment production, an unsuitable thread may contribute to frequent thread breakage, skipped stitches, unstable seams and repeated machine stops. When the same problem occurs across multiple sewing machines, even a small issue can affect overall production efficiency.
The correct thread should match the fabric, needle, stitch type and required seam strength. A thread that is too heavy may create bulky or unattractive seams on lightweight fabrics, while a thread that is too fine may not provide enough strength for heavier sewing applications.
For garment factories and bulk buyers, this means the cheapest thread is not always the lowest-cost choice. Stable sewing performance, consistent quality and the correct thread specification can help reduce interruptions, rework and unnecessary production losses.
Why Does Polyester Sewing Thread Keep Breaking?
Frequent thread breakage can slow down production and increase rework. The cause is not always the thread itself—it may also come from the wrong thread size, needle mismatch, excessive tension, high-speed friction or incorrect machine settings.
Simply switching to a thicker thread may not solve the problem. The thread, needle, fabric and machine settings need to work together for stable sewing performance.
How to Choose the Right Polyester Sewing Thread
Before ordering, consider your fabric type, sewing application, needle size and required seam strength. 40/2 is widely used for general garment sewing, while heavier or finer applications may require different thread sizes.
If you are unsure which size to choose, send us your fabric or product information, required thread weight or length, colors and quantity. We can help confirm a suitable specification and provide samples for testing before bulk production.
