Sewing Machine Tension Guide - How to Identify and Fix Problems
Tension problems are one of the most common sewing machine issues - but incorrect threading causes more tension problems than anything else. Always check that first before touching the tension dial.
Understanding tension
Tension is the balance between the upper thread and the bobbin thread. When balanced correctly, the two threads lock together in the middle of the fabric - you can't see the upper thread from the back and you can't see the bobbin thread from the front.
- Most machines have a tension dial numbered 0-9 - a higher number means more tension, a lower number means less
- The default setting on most machines is around 4 - start here if you're not sure where to begin
- A balanced stitch looks identical on both sides of the fabric with no loops, puckering or pulling on either side
Before adjusting the tension dial - check these first
Tension adjustment should always be the last thing you try, not the first. These checks resolve the majority of tension problems without touching the dial at all.
- Re-thread the machine completely with the presser foot raised - incorrect threading is the single most common cause of tension problems
- Check the bobbin is inserted correctly and the thread is pulled through the tension slot
- Make sure the thread is flowing freely from the spool and isn't catching or snagging
- Check the needle - a blunt or wrong needle can cause uneven stitching that looks like a tension problem
- Make sure the top and bobbin threads are the same weight - mismatched threads cause tension imbalance
- Clean any lint from around the bobbin area and tension discs - build-up here can affect how the tension discs grip the thread
Identifying and fixing tension problems
Use the table below to match what you're seeing to the correct adjustment. Always make small changes and test on scrap fabric after each one.
| What you see | Cause | What to do |
|---|---|---|
| Bobbin thread visible on top of fabric or fabric puckering | Upper tension too tight | Turn the tension dial to a lower number |
| Upper thread visible on underside of fabric or loops on back | Upper tension too loose | Turn the tension dial to a higher number |
| Stitches puckering on lightweight fabric | Tension too tight for fabric weight | Reduce tension slightly and increase stitch length |
| Thread breaking | Tension too tight or threading issue | Re-thread completely, then reduce upper tension if needed |
| Stitches uneven or inconsistent | Threading issue or bobbin problem | Re-thread completely and check bobbin is seated correctly |
A note on bobbin tension
In the vast majority of cases, only the upper tension needs adjusting. The bobbin tension is factory set and should be left alone in normal use.
- If adjusting the upper tension in both directions doesn't resolve the problem, the bobbin tension may need attention
- Bobbin tension adjustment should be treated as a last resort - if you're not confident doing this yourself, get in touch and we can help
Tension tips for different fabrics
There's no single tension setting that works for every fabric - always test on scrap before starting your project.
Lightweight fabrics
Slightly lower tension and a longer stitch length. Too much tension causes puckering on fine fabrics.
Heavy fabrics
Slightly higher tension to pull the stitch together through thicker material.
Stretchy fabrics
Lower tension and use a stretch stitch or slight zigzag - straight stitches at normal tension will break under stretch.
Specialty threads
Metallic and invisible threads need lower tension and a slower speed to behave - refer to your machine manual for guidance.
Still having trouble? We're here to help.
If you've worked through the guide and your tension still isn't right, get in touch and our team will take it from there.
Still stuck? We are happy to help.
Our service team has seen every machine in our range and can usually diagnose problems over the phone.
