What is a Twin Needle and How to Use One

This post is a featured lesson in our free ebook, Beginner's Guide to Sewing Knit Apparel. Download it for free here!

In this tutorial we will be covering the tool that everyone hemming on a sewing machine needs – a twin needle! 

Twin Needle

So if you look at the bottom hem of any of your store bought clothes you’re going to see a stitch with two or three top threads and a series of looper stitches along the back. These stitches are made with a coverstitch machine. If you don’t have access to a coverstitch machine, you can achieve a very similar look with a twin needle on your sewing machine.

Coverstitch vs. Twin Needle

The twin needle is going to give you two uniform rows of top stitches just like a coverstitch machine. The back of the stitch will be different, of course, but it accomplishes a similar task on the cheap.

Not only does this double stitch look more professional, but it also provides a little added stretch to prevent any stitches from popping. This is especially true when coupled with some stretch thread. 

Types of Twin Needles

The two different kinds of twin needles you’ll be looking for will be a stretch twin needle and a ballpoint twin needle.

Stretch Twin Needle: A stretch twin needle has a smaller rounded tip and should be used for highly elastic fabrics such as spandex or scuba.

Ballpoint Twin Needle: A ballpoint twin needle should be your go-to for all other knit fabrics.


Another thing to keep in mind as you are shopping for a twin needle is the width.

The width of your twin needle refers to how far apart your two needles (and stitches) are spaced. It is rare that you find a twin needle too wide to fit down past the sewing plate, but it can happen. This is dependent on your particular sewing machine and presser foot. Keep your receipt just in case you need to return it for that reason.

How to Install And Use A Twin Needle

You’ll start by simply replacing your single needle with the twin needle just like you would any other needle. The next thing you’ll have to do is get yourself a second spool of thread. Or you can wind up a bobbin with your current spool so that your stitches match.

Once you have your two spools ready, you’ll need to get something to hold the second spool. For this, I just taped a rounded stick/dowel onto the side of my machine. See the picture:

Twin Needle Set Up

Then while keeping your two threads pinched in between your fingers, you’re going to thread them through your machine as you would with a single thread. Do your best to prevent any twisting as you go.

Thread on Machine

The last step is to thread your two needles. Once again, do what you can to keep your threads parallel with one another, rather than letting them get all twisted up.

Twin Needle Threaded

Tips for Making Your Twin-Needle Experience Even Better

Fixing the “Tunneling” Issue

If you just installed your shiny new twin needle and you are getting a tunneling effect on your top stitch, chances are that your bobbin tension needs to be lowered. The bobbin is looping through two different threads so the lower tension will keep it from pulling them towards one another, creating that tunneling. If you think your bobbin tension is low enough, try increasing your needle tension.

Using Stretch Thread

In another tutorial we talk about stretch thread and wooly nylon so I won’t go into too much detail here, but suffice it to say that using one of these two in your bobbin will help make that top stitch more flexible, preventing popped stitches.

Making It Look More Professional

Topstitching can be a wonderfully personalized touch to your knit clothing. Its function is to help reinforce certain seams or keep certain places in your garment laying flat. But more obviously, it provides an aesthetic touch that can be personalized to your taste. The two things you can do to really make your topstitching look more professional with a twin needle are:

  1. Lengthening your stitches – The longest length on your machine
  2. Using thicker topstitching thread – Makes the topstitch bolder

Now You're Ready!

Install a twin needle on your sewing machine and practice top stitching scrap pieces of fabric folded over. Adjust your tensions until you achieve a nice flat top stitch.

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