What is a good stitch length?

Threads Magazine recently published an article called 10 Better sewing Habits with tips from various sewists. Peggy Sagers said that the proper stitch length for construction seams- not basting- is 3.5mm.

Peggy’s reasoning is when tension is put on a garment, the threads will snap at 3.5mm. At 2.5mm the fabric will rip.


2.5mm stitch length on a bag I made.
2.5mm stitch length looks very tiny on a bag I made.

My sewing machine automatically starts sewing at 2.5mm. My basting stitch is programmed to be 3.5mm. I’m guessing that most people sew at 2.5mm too.

While I haven’t had time to test out these different stitch lengths, I have noticed that the fabric of my vents will sometimes tear right at the seam line.

Stitch detail on a tote I bought. It is much longer at 8mm for the top stitching & seam construction.

In contrast, the tote bags I’ve bought haven’t ripped, even when weighed down with heavy glass bottles. The one seen above has a stitch length of a whopping 8mm. However, for the main seams of the bag the stitching was doubled up.

Any thoughts on this? At what stitch length do you sew? Any ex-industry workers out there who can tell us what the industry standard is?



18 thoughts on “What is a good stitch length?

  1. I’ve always used 2.5mm for notmal sewing, 3mm for topstitching and 4mm for gathering. I can’t say I’ve ever had a huge problem with “shearing”. I use Gutermann sew all unless I’m sewing silk.

  2. I was very surprised by this article too! Some of the advice given totally made sense to me, but I found myself really wondering about stitch length.. My sewing machine is a vintage Bernina and I’m not sure the numbers correspond to stitch length (I should check), but 3.5 mm sounds huge! I will try to make an effort though and give a try at increasing my stitch length 🙂

  3. I’m intrigued by this too! I used to sew at 2mm purely because it was the middle setting on the dial! I use 2.5 now (after reading the same Threads article) but 3.5mm is too close to my basting stitch of 4mm… Hmm, if I get time I may do some unscientific experiments! I usually use Gutermann sew all and I’ve never had thread or fabric fail on me!

  4. Yes, it does depend on what the thread is made of; if you use silk, it could be too strong compared to the fabric. But it’s more the combination of thread, stitch length, and the weave of the fabric; if you use a too-small stitch on a loosely-woven fabric (relatively loose, like linen), it will be more prone to tearing– and more so if the thread fiber isn’t compatible. And it’s a whole different thing with knit fabrics! It takes experimenting, but in my experience, I agree about using a longer stitch length in general.

  5. I was shocked at this too. I usually sew between 2 and 3 on my machine. It’s manual so it’s easy to spin the dial. I will have to start paying attention to how things wear.

  6. I automatically change my stitch length to 3.5 and always have. I think it is because I come from an industry background. I find that it is the best overall stitch length.

  7. I read that article too, and I am going to try increasing the stitch length and see what happens. I will do it the first time on something that isn’t a heavy wear kind of garment though. I’m too chicken to try it on a “good” item.

    • It does seem so odd, but I’m going to give it a try & see. Although I doubt I would always remember to adjust my stitch length from the automatic 2.5. Technology & living in a city has made me so lazy & impatient it just seems like too much work to always switch! 🙂

  8. Interesting discussion! I usually sew at 3mm (although I drop it down to 2.5mm for tight curves) and baste at 4mm (which seems to be the longest stitch on my machine?) I just chose my stitch length somewhat arbitrarily however – it’s not the longest, and it’s not so small it’s a pain to unpick if needed. (Unpicking 2.5mm length stitches really isn’t so fun. Not that any unpicking is fun, but there are different levels of not-fun-ness and 2.5mm is right up there I reckon.)

  9. interesting. my jaw dropped when i read 3.5 for normal sewing. i’d feel like i was basting everything together! i usually sew at 2.5, and i have never had any fabric rip, though i have noticed the rare spot of popped stitches at points of tension. hmmm. i’ll have to ponder this!

  10. I like to use a 3mm stitch where possible, but it does vary with what I’m sewing. My machine defaults to 2.5mm too, but it’s basting is 6mm. It’s got a lot of default settings that I don’t always agree with, but then I don’t like being told what to do!
    I find if the stitch length is too short the seam can pucker, plus it’s a nightmare to rip out, should you need to.

  11. It depends on your thread as well…I never use cotton, I am not a quilter so there is none of that in my sewing room unless it is for decorative thread on jeans hemming. people bring me the crappiest cheap thread to sew their garments, I hand it back and use Mettrosene poly. Folks say poly stretches and puckers but if you sew at a normal pace and not brake-neck speed it will stay flat and nice.

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