Ask CRAFT: Sewing Machine Tension

Craft & Design Yarncraft


Why is it that sewing machine tension can be such a bear to deal with? Here are some symptoms of tension problems:

  • thread breakage
  • skipped stitches
  • knotting or jamming
  • top/bottom thread visible on the other side of the seam

Many of these problems can be alleviated by giving your machine a thorough cleaning and making sure it’s threaded properly, but in some cases there’s a bigger problem. Before taking it to the shop, you can change out a few parts to help troubleshoot and isolate the problem.

Plastic bobbins

If you have been using plastic bobbins, they can wear out. If your needle catches the bobbin it can nick it, causing the thread to catch. Swap out your plastic bobbin for a metal one to see if it fixes the problem. Plastic bobbins can be gently sanded with a nail file to get out nicks. Over time the plastic can wear down as well from all the friction of the bobbin casing and thread, putting the bobbin out of commission.


If your needle is bent, dull, or inserted improperly, this can also cause tension problems. A bent needle is more likely to nick your bobbins, so watch out! Make sure you’re using the right kind of needle for your thread and fabric; the wrong one can skip stitches (like using a sharp instead of ball-point needle on knits) or break your thread (if, for instance, the eye is too small).


Use good-quality thread. I found a site that shows magnified images of many different brands, showing how tight, loose, or fray-prone different types are. A poor quality thread causes more friction on the plastic parts of your machine and can wear them out prematurely. Which brings us to the biggest and possibly most expensive problem…

Tension discs

Most modern machines are made with plastic tension discs. Metal parts are great for durability and industrial use, but they are meant to be used all the time or they gum up. Plastic parts means a lighter machine and fewer maintenance and lubrication concerns when it comes to less-than-everyday use. However, as mentioned, fuzzy thread tends to wear down plastic parts over time (we’re talking years, here). Plastic tension discs can become grooved, meaning you’re out of luck when it comes to adjusting it, since they can’t get a reliable grip on the thread. The tension discs are usually pretty far inside your machine, which makes it really hard to get in there and see if that’s your problem.

NM State has a good guide for regular sewing machine maintenance to help you through the processes mentioned above. If you’ve tried everything short of taking the machine apart yourself, take it to a professional and explain all you’ve done. It’s possible that your tension discs are fine and your timing is just off, which is relatively easy for a technician to adjust. Depending on the repair estimate, you might declare it time to upgrade to a new machine, vowing to only use high-quality thread (a small investment to protect your new machine). Your model might have easily-replaceable tension discs, but some manufacturers don’t sell the replacement part. Thanks to Debbi Schlegel for her help on this topic. If you’ve got advice about tension problems, leave it in the comments below!

If you have a question for Ask CRAFT, shoot me an email at, or drop us a note on Twitter! We’d love to answer your crafty questions on any topic: technique, projects, crafty culture, or anything else! Each week the answers are here; include your name, where you’re from, and your website or blog if you have one!

14 thoughts on “Ask CRAFT: Sewing Machine Tension

  1. mj says:

    Thanks for posting this! I was having problems with skipped stitches last night that were (magically, it seemed) solved by switching to a better quality thread. It’s nice to know there was a real reason why that worked. Tonight the problem repeated itself briefly when I got to the end of a bobbin, but I might have also slowed down the speed of my stitching.

  2. becka says:

    Also make sure you have the right bobbin for your machine. There are lots of different kind of bobbins and it’s easy to get the wrong one. I taught a class once with machines that were terrible. We finally figured out that someone had bought the cheapest generic bobbins from the $1 section – which were slightly the wrong size for our machines. Replace the bobbins with the right one and problem solved!

  3. Sarah says:

    Becka is exactly right that you should make sure you’re using the right bobbin for your machine, and this includes not using metal bobbins for certain machines. My machine (a Janome) will not operate correctly with a metal bobbin. I know some Vikings are the same way. Make sure to read your manual (and if you bought you machine used, you can and should order one from the manufacturer) and check to make sure you are not putting a metal bobbin in a plastic-only machine.

  4. miss melissa says:

    Thank you for this information! I taught myself to use an older sewing machine… and I feel I’m always running into tension problems. I always look for the way to fix it myself–if I can figure out what’s going wrong, I can make sure not to repeat my mistakes.

  5. Pinky says:

    The main reason people have tension trouble is that they fiddle with their tension while their presser feet are up. It is one of the first rules that I was taught about sewing machines (both my mother, and grandmother were dressmakers and I have a degree in design). You must NEVER EVER touch your tension unless your presser foot is down (engaged). If you do you will mess up your tension and every thing you do to fix it will just make it worse. If you follow this simple rule your machine will buzz along without fail. I still use a machine I got for graduation in 1977 and it has never given me any tension trouble. I sew professional and I have never had to had it serviced I just keep it clean, oiled, and like I said, I never touch the tension without the presser foot down. Follow this rule and you will be amazed how well your machine works.

  6. Heather says:

    Yes, I agree with the comments about making sure you are using the right bobbins for your machine. I used any I could find for my Janome, and caused a $150 repair bill. the sewing machine shop sent them back in a bag labelled ‘DO NOT USE!’

  7. Benjamin says:

    Hi I am sewing machine mechanic, ill be happy to help you with your sewing machine mechanical problems and provide you advice.

Comments are closed.

Discuss this article with the rest of the community on our Discord server!

Becky Stern is a Content Creator at Autodesk/Instructables, and part time faculty at New York’s School of Visual Arts Products of Design grad program. Making and sharing are her two biggest passions, and she's created hundreds of free online DIY tutorials and videos, mostly about technology and its intersection with crafts. Find her @bekathwia on YouTube/Twitter/Instagram.

View more articles by Becky Stern


Ready to dive into the realm of hands-on innovation? This collection serves as your passport to an exhilarating journey of cutting-edge tinkering and technological marvels, encompassing 15 indispensable books tailored for budding creators.

Escape to an island of imagination + innovation as Maker Faire Bay Area returns for its 15th iteration!

Buy Tickets today! SAVE 15% and lock-in your preferred date(s).