23 Oct 2008, 12:58am
Sewing Machines


Howto set your tension

I have seen many articles telling you what your seams should look like at the proper tension, but all of them have been really vague about how to go about adjusting the tension to get that seam.

First you need some kind of starting point. Older Singer machines were factory set to sew medium weight fabric with number 50 mercerized cotton thread and a number 14 needle with the tension dial set at 3. Nowadays that needs some explanation. As far as I can determine by medium weight fabric they mean something like a man’s dress shirt is made from. For thread I am using Coats & Clark Duly Duty Plus Polyester. I think it is a bit heavier than #50 cotton size wise (I am not real sure of that as I can not find any cotton thread around here to compare it to), but Poly stretches a bit so you usually use a slightly lower tension, because of that it seems to be about right. I also picked up some #12 Schmitz Sharp needles. Anyway I set my machine up so the dial is at 3 with that combination, and it seems to give a good range of setting for other thread and needles.

A side note: I said in the article about Needles, Thread, Fabric and Tension that all of them make a difference. With a bit more experience I now think the most important thing is to match your needle to your fabric. I found that medium heavy Duck breaks #11, and bends number 14 needles, but works fine with #16 needles. At the moment I am using #12 and #16 sharp point needles for most everything.

Now to the matter at hand, how to go about setting your tension when you have no idea what is going to be correct. Start with the dial set at 3 or the center of the dial if you have no idea what the machine is set for. Run a bit of a seam on a piece of dress shirt weight fabric folded double, a couple of inches is enough. I suggest marking one side so you can easily tell which side is the top. Examine the seam.

Step One:

If there are loops on top reduce your tension two dial marks.

If there are loops on the bottom increase the tension two dial marks

If there are no loops go to the next step

Step Two:

If it looks like sewing on the bottom, and just a straight thread on top, increase your tension one mark.

If it looks like sewing on top, and just a straight thread on bottom reduce your tension one mark.

If it looks like sewing on both sides go to the next step.

Step Three:

Look very carefully at the stitching,

If it looks loose on the bottom increase the tension ½ the amount you changed it the last time.

If it looks loose on the top reduce the tension ½ the amount you changed it the last time.

Repeat until you can not tell any difference in the two threads.

You programmer types will recognize that we and using a binary search to find the correct tension setting. For others what that means is we are moving the setting past what it needs to be and then back half way. We are reducing the error 50% or more each time we do that. Going from loopy to good enough only takes five steps; 2, 1, ½, ¼, 1/8. A couple of steps more and you are moving the dial only a hair and have it about as close at a really well set up machine will do because there is some slop in the train and it will wobble that much. You will also notice that correct tension is only about 1/8 a dial marking from incorrect.

Make notes of what is correct with each needle/thread combination you use, and you will be able to set the dial close next time you use that combination. From there it only takes one or two steps to get it just right.

Oh my gosh!! FINALLY someone who has given a clear, comprehensive tutorial to setting tension. I’ve been sewing for 27 years and in all that time, I’ve never read a thing that gave me clear instructions on what to look for and how to fix it when dealing with tension. (Not even the sewing machine manual! lol)

Thank you so much, Tom!

Kind regards,

Jen, CA

Thank you for your comment, Jen. I have gotten a couple of emails similar to your comment and I believe someone mentioned this article was helpful in a comment to another post.

I do not know why there is such a lack of info about setting the tension. I imagine that in the old days it was something you learned in sewing class or from an apprentice program. I do know that the techs I have talked to seem to have only the vaguest idea about how to go about it.

If this method does not work the sewing machine needs servicing because it is out of the range that can be set with the dial.

One advantage I have is that I have technical skills in so many areas that I can usually figure out a way to fix about anything I come across. Sewing machines are kind of fun to tinker with.

24 Feb 2010, 2:20am
by Danielle

What should I do if the seam makes the shirt look as though it’s “ruched” ?

I have a Singer, and i was wondering if there like a list of what fabrics have what tension number… Or does it vary between machines? I’m assuming one side of the stitch line gathers an extra amount of thread is because of the tension….. Am I wrong? LoL. Please HELP.

No, there are no standard settings, it is strictly a trial and error process. But, my article is about the best info out there for making it easier.

Yes, you are correct, the threads being tighter on one side means the tension is not set properly. If you go all the way to one extreme or the other and it still is not even on both sides, then the machine is out of adjustment.

Generally a straigt stitch machine is setup to about 4-5 with shirt weight fabric with thread & needle appropriate for that fabric. Zigzag machines are set for about 7, settings below 5 being appropreate for zigzag stitches. However, even sewing machine techs sometimes know little about setting the tension, so usually the method described in my article works best.

i still have my first machine the singer 4530. unfortunately i do not have the manual. lately i have had a lot of problems with thread gathering on the underside of my fabric. i am pretty sure it is the tension. i do not even reallly know what all of the knobs are for on my machine. too many with no explaination. just numbers and stitch graphics. can you offer any explaination of the dials? thank you! Lisa

A long time later, I am adding this comment because I had a tension problem on my Singer 750 after I had not used it for a couple of years.

What I found out is that the internal (normally a service adjustment) tension adjuster had worked itself loose full turn. Now, I might have expected that from vibration of running the machine, it had just been sitting. I went through and oiled everything that was supposed to be oiled, cleaned everything that was supposed to be cleaned. But I could not properly adjust the tension.

Remember, I said when that happens the machine needs to be serviced? Well it did, and it was an easy fix, if you know what to look for and how to fix it. But it also points up the fact that a machine can go out of adjustment just because it was not being used.

Something to think about.


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