How to Thread a Serger: Easy Threading 4 Thread Overlocker

If you have ever used a serger machine, then you already know that threading a serger machine is sometimes complicating part of the machine. Serger machines come with a complete threading guide, and many of the modern serger machines come with a pre-threaded setup, but even that threading guide and one-time setup are not enough for some people.

Here I will share a complete step-by-step guide to thread a modern 4-needle serger. This single guide will be sufficient for any modern serger machine. Once you have learned and practiced threading a serger properly, overlocking will become a lot easier for you.

Things you need

1. Serger machine.
2. 4 spools or cones of thread.
3. Tweezers.

Preparing serger before threading

Prior the actually threading the serger, we first need to set up the serger. For that

1. Uncover the front access panel.
2. Place all the thread spool/cone on the spool needle and secure it properly with the thread cover.

We will break the section into 4 parts. These parts also give you the order in which you should ideally thread your serger. This order is as below.

1. First, we will thread Lower Looper.
2. Then we will thread the Upper Looper.
3. Then the Right/Inside Needle.
4. Lastly, the Left/Outside Needle.

Also, almost all modern serger machines come with a color-coded guide, which would help you thread all the threads separately.

So let’s just jump into a complete step-by-step guide to thread a serger. I will be using my Brother 2504D serger, yet threading other sergers will also be the same.

Step by Step Procedure to thread a Serger

Part 1: Threading Lower Looper

1. Start by threading the upper looper. Pass the thread through 1st and 2nd guide in the thread tree.

2. Now you have to pass the thread through the cavity of the tension disk. For that, first, lift the tension release lever. Then press the thread inside the cavity. You would feel a subtle click when it settles properly beside the tension disk. Pass the thread to the end of the crack and reach the access panel.

3. First, pass the thread through the 5th guide that lies right below the crack in the access panel. Then pass it through the 6th and 7th, and 8th guides.

4. Now the last guide is a little triangular channel that is to be slid out using the toggle switch.  When the 9^th guide slides out, pass it through that channel.

5. Now you will find another figure that points inward and has a tiny hole. This is our lower looper. Pass the thread through its hole. Make sure that you pass the thread from the front to the back of the machine.

Part 2: Threading Upper Looper

1. Now is the turn of the upper looper. Keep in mind that the first four steps for all four loopers/needles are exactly the same.

2. Repeat the first four steps of part 1 for threading the upper looper as well

3. Now pass the thread from the 5th guide that resides right below the tension cavity.

4. From the 5th guide, pass the thread through other guides in the front access panel.

5. Now, at last, there you will find a tiny finger with a hole in it. That’s our upper looper. Pass the thread through that looper from front to back. You can also use tweezers to thread that tiny hole.

Part 3: Threading Right Needle

1. Repeat the first four steps of part 1 for the right needle. At the same time, the rest of the procedure is exactly the same as that of a standard machine.

2. Pass the thread through channel 5, which is right above the needle head. At guide 6, there is a divider. Make sure that you pass it through the right side of the divider.

3. Pass it from the loop of guide 7 that lies right above the needles.

5. Now pass the thread through the right needle from front to back.

Part 4: Threading left needle

All the steps for threading the left needle are the same as threading the right needle.

• 1. The first three steps of part 3 are similar for the left needle as well. Just at guide 6 you need to pass the thread through the left side of the divider.
• 2. Now pass the thread through the left needle that resides right next to the right needle.

Setting the Thread in Presser Foot

Collect all the threads to the left. Then pass the threads through the gap in the foot and then around the back of the foot. Close the front lid, re-engage the tension disks, and your serger is ready to be used.

Testing the threaded Serger

Now that you have threaded the serger, it is time to test how well you have threaded.

1. First, collect all four thread ends at the back of the machine.
2. Start rotating the wheel of the serger anti-clockwise with your other hand.
3. While rotating, ensure that you don’t pull the threads with your hand. Instead, you just keep them stretched while rotating the wheel.

If neat and clear chains are made, you have threaded the serger correctly.

If you are struggling with an inappropriate thread, then here are our top recommended serger threads.
And here you can find the best serger sewing machine.

Concluding Remarks

Now you have learned how to thread a serger and tested it yourself. You can use the same technique for every modern 4-thread serger machine. I hope that my efforts to break the whole section into parts helped you a lot while learning the procedure.