Complete guide on how to thread an overlocker

Complete guide on how to thread an overlocker

an overlocker machine is the perfect tool to take your sewing to the next level. Learn how to thread an overlocker with our guide.

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Published: May 21, 2025 at 3:00 pm

Complete guide on how to thread an overlocker

Once you've purchased your overlocker, the first thing you'll need to learn is how to use it.

Threading your overlocker machine correctly is vital for achieving the best results, but it's a bit fiddly to start with. But we're here to help, follow our guide on how to thread an overlocker to make this task less daunting.

Singer overlocker SE017

If you're looking to buy a new overlocker machine or want to find out more about what they're used for, check out our guide to the best overlocker machines.

How to thread an overlocker machine

Threading an overlocker can be one of the most daunting things about owning one. Unlike a sewing machine where there is only a needle to thread, there are two needles and two loopers to deal with on an overlocker and lots of poking around inside the machine!

The most important thing to remember is to refer to the manual about to thread your specific machine. Some machines will also have a handy video guide to help you.

Most overlockers require you to thread them in a particular order for them to function – usually from right to left: lower looper, upper looper, right-hand needle, left-hand needle. Each looper/needle will have a different colour to help show which is which.

This is a general threading guide for a Janome overlocker and will give you a good idea of threading, even if you own a different machine, but do refer to your manual for anything particular to your model.

overlocker machine - pexels-shkrabaanthony

Threading the lower looper

  1. Raise the presser foot. This opens the tension discs, allowing you to pass the threads through them.
  2. Open up both the looper cover and the side cover.
  3. Place a thread spool on the spool pin to the far right.
  4. Draw up the thread through the right-side thread guide, from the back to the front then slide the thread under the top cover thread guide.
  5. Insert the thread through the tension discs, ensuring it sits between the discs.
  6. Follow the illustrations on your machine to pass the thread through the thread guides.
  7. Turn the handwheel towards you until the needles are in their uppermost position. Push the lower looper thread guide to the left, which will pop the next two lower looper thread guides to the right to make them easier to thread.
  8. Pass the thread through the remaining lower looper thread guides and then through the eye of the lower looper. 
  9. Place the thread under the presser foot, towards the back of the machine.

Threading the upper looper

  1. Place a thread spool on the spool pin second to the right.
  2. Draw up the thread through the second to the right thread guide, from the back to the front then slide the thread under the top cover thread guide.
  3. Insert the thread through the tension discs, ensuring it sits between the discs.
  4. Follow the illustrations on your machine to pass the thread through the upper looper thread guides.
  5. Pass the thread through the eye of the upper looper.
  6. Place the thread under the presser foot, towards the back of the machine.
Threads

Threading the right-hand needle

  1. Place a thread spool on the spool pin second to the left.
  2. Draw up the thread through the second to the left thread guide, from the back to the front then slide the thread under the top cover thread guide.
  3. Insert the thread through the tension discs, ensuring it sits between the discs.
  4. Follow the illustrations on your machine to pass the thread through the front cover thread guides and the take up lever.
  5. Insert the needle through the right-hand slot of the needle thread guide plate and through the next needle bar thread guide.
  6. Use the handwheel to raise the needles to the highest point and thread the right-hand needle from front to back.
  7. Place the thread under the presser foot, towards the back of the machine.

Threading the left-hand needle

  1. Place a thread spool on the spool pin to the far left.
  2. Draw up the thread through the left-hand thread guide, from the back to the front then slide the thread under the top cover thread guide.
  3. Insert the thread through the tension discs, ensuring it sits between the discs.
  4. Follow the illustrations on your machine to pass the thread through the front cover thread guides and the take up lever.
  5. Insert the needle through the left-hand slot of the needle thread guide plate and through the next needle bar thread guide.
  6. Use the handwheel to raise the needles to the highest point and thread the left-hand needle from front to back.
  7. Place the thread under the presser foot, towards the back of the machine.
Best overlocker sewing machines

Creating a thread chain

  1. Pull all four threads to the left of the presser foot and hold on to them.
  2. Lower the presser foot.
  3. Close both the looper cover and the side cover.
  4. Use the foot pedal to run off a chain of stitches about 10-15cm long.

Tying threads if your overlocker machine already has threads in place

There is an alternative threading method which you can use and may find easier if your machine already has some threads in place (for example if you're just looking to add more when it's running out).

  1. Use a flat reef knot to tie your new thread to the old thread.
  2. Ensure the pressure foot lever is up
  3. Set the tension dial to 0
  4. Wind your newly tied threads through your machine using the handle
  5. Ease the knotted part of your thread through as they can get caught or stuck
  6. Stop just as the knot reaches the eye of your needle
  7. Snip just before the knot
  8. Thread through the needle
  9. Once you've threaded reset the tension

Air threaders

Some people really struggle with threading an overlocker due to being a beginner and anyone who has difficulty seeing or struggles with dexterity might find threading an overlocker particularly hard, especially when it comes to threading the bottom loopers.

If you do need a hand with threading, there are now overlockers that have air threading to assist you. These work by using a blast of compressed air to take the thread through the loopers to where it needs to be, leaving you with more time free to sew!


For a more detailed guide to using your overlocker, we'd recommend watching Sew Essentials video below.


If you're after even more information on how to use an overlocker machine, you'll find a brilliant bonus booklet in issue 134 of Simply Sewing magazine. Order a copy online or download a digital issue.


Practice makes perfect when threading an overlocker machine

Even sewists who've been using machines for years will find overlocker machines a bit confusing at first, so it's important to take your time and refer to your user manual. You'll find it easier to set up your machine in good light or with a lamp nearby, and if you find yourself getting stressed take a few minutes away and come back to it with fresh eyes.

Room for all your machines

The addition of an overlocker machine means one more thing to find space for. Make sure you've got enough room to work in comfort with our pick of the best sewing machine tables on Gathered.

Sewing machine tables 3