There’s nothing more frustrating than getting into your sewing groove, only to hear that dreaded snap. If your thread keeps breaking on the sewing machine, a few simple checks can help you find the cause.
While the thread itself can sometimes be the problem, thread breakage often comes down to your needle, bobbin, tension, threading technique, or machine maintenance. The good news? Most of these issues are easy to check and fix.
1. Check Your Needle When Thread Keeps Breaking
One of the most common causes of thread breakage is using a dull, damaged, or incorrectly sized needle. The wrong needle can create unnecessary friction, causing your thread to fray or snap as you sew.
As a general guide, finer threads, such as DecoBob™ 80wt thread, can work with smaller needles. Heavier threads, such as 12wt, need a larger needle with a bigger eye so the thread can pass through smoothly. Always choose your needle type and size based on both your fabric and thread.
How to fix it: Replace your needle and check that it is installed correctly according to your machine’s manual. Change it after approximately eight hours of sewing, or sooner if you notice damage or stitching problems.
2. Make Sure You’re Using the Right Bobbin
Your bobbin plays an important role in smooth stitching. An incorrect bobbin size, uneven winding, or improper insertion can interfere with thread delivery and cause problems as you sew.
First, check your machine’s manual for the correct bobbin type. Even bobbins that look similar can have different dimensions.
How to fix it: Make sure your bobbin is evenly wound and inserted in the direction your machine requires. Follow the bobbin threading path carefully, and replace any damaged bobbins.
For a convenient option, we recommend DecoBob™ 80wt pre-wound bobbins. They are uniformly wound and glue- and wax-free. The fine 80wt thread also helps reduce bulk in your stitches for a cleaner finish.
DecoBob™ pre-wound bobbins are available in Class 15, L, and M sizes. Confirm which size your machine accepts before purchasing.
3. Check Your Thread Tension
If your thread keeps breaking, the upper-thread tension may be too tight. Excessive tension puts stress on the thread as it passes through the machine, causing it to snap while forming a stitch.
However, incorrect threading can also create tension problems. Before changing your settings, rethread the machine with the presser foot raised and check the bobbin placement.
How to fix it: If the upper thread still breaks, slightly lower the upper-thread tension. Sew a test seam on scraps of your project fabric, making one small adjustment at a time.
If your bobbin thread breaks, check for incorrect insertion, tangled thread, or lint around the bobbin case. Consult your machine’s manual before adjusting bobbin-case tension.
For a standard balanced lockstitch, the upper and bobbin threads should meet within the fabric layers, without unwanted loops or puckering.
Whenever you change your fabric, thread, or needle, test your stitch settings before sewing your project.
4. Raise the Presser Foot Before Threading
One simple step that sewists sometimes overlook is raising the presser foot before threading the machine.
On most domestic sewing machines, raising the presser foot opens the tension discs. This allows the upper thread to settle properly between them. Threading with the foot down can leave the thread incorrectly seated, resulting in uneven tension and stitching problems.
How to fix it: Raise the presser foot and position the needle according to your machine’s manual. Then, carefully follow the entire upper threading path, including the take-up lever.
Once you have finished threading, lower the presser foot before sewing a test seam.
5. Keep Up With General Machine Maintenance
Sometimes, your machine just needs a little attention!
Lint, dust, and loose thread can collect around the bobbin area and feed dogs. This buildup can interfere with thread movement and contribute to stitching problems.
How to fix it: Turn off and unplug your machine before cleaning. Follow your machine’s manual to remove lint and loose thread from accessible areas. Only oil the machine if the manufacturer recommends it.
If thread keeps breaking after these checks, a burr or damaged part may be catching it. A qualified sewing machine technician can help identify persistent problems.
Quick Checklist When Your Thread Keeps Breaking
Before you start sewing again, check these five things:
- Is your needle fresh, correctly installed, and suitable for your fabric and thread?
- Is your bobbin the correct type, evenly wound, and properly inserted?
- Have you rethreaded the machine and tested the upper-thread tension?
- Did you raise the presser foot before threading and lower it before sewing?
- Is your machine clean and maintained according to its manual?
Make one adjustment at a time and test on scrap fabric after each change. A few simple checks can help you spend less time troubleshooting and more time enjoying your next project.
Ready to choose thread for your next project? Explore WonderFil’s specialty threads and find options suited to your sewing technique and desired finish.