What Is An Overlocker?

Basic of an Overlocker Sewing Machine

As a professional, you can agree that it is almost impossible to sew fabrics neatly without using an overlocker. An overlocker is an extremely versatile machine that sews using 3, 4, or even 5 threads at a go to neaten edges and cut off excess fabrics.. wow!

What is an overlocker then? An overlocker is a fast sewing machine that gives a professional finishing because it encases raw edges with an overcast stitch. With an overlocker, you can achieve a variety of fancy rims, and they are perfect for attaching elastic fabrics neatly. Most times, it can also be referred to as “Serger.”

Using an overlocker can be quite daunting if you are a beginner, and even to a professional, the threading can be time-consuming. For beginner overlockers see our post What Are The Best Overlockers For Beginners.

Serger vs. Sewing Machine: Key Differences

So what is the difference between a sewing machine and an overlocker, do they do the same thing?

An overlocker, also known as an serger, simultaneously trims the fabric and encases the edge in stitches, offering a neat finish. In contrast, a sewing machine really only focuses on stitching pieces of fabric together without cutting it.

Overlocker Features:

  • Performs sewing and edge finishing in one step.
  • Operates exclusively on the left side of the needle.
  • Equipped with a blade for trimming fabric while sewing (this can be deactivated).
  • Utilizes 3 to 5 threads for an overlock stitch, ensuring a durable and elastic seam.
  • Prevents fabric edges from fraying or unraveling.
  • Designed with a compact neck for swift operation.

Sewing Machine Functions:

  • Tackles sewing tasks individually.
  • Capable of sewing on both sides of the needle.
  • Requires fabric edges to be cut in advance as it doesn’t include a cutting feature.
  • Employs 1 or 2 threads from a top spool and a bobbin, which may result in less robust stitches.
  • Produces seams that may lack stretchability.
  • May lead to frayed fabric edges unless edges are hemmed.
  • Features a longer neck, offering versatility in sewing speed and technique based on the model.

So the key distinctions is the serger’s ability to cut fabric and use an overlock stitch for durable, stretchy seams, whereas sewing machines offer more versatility in stitch types and sewing speed but don’t inherently trim or finish edges.

Questions to answer before buying an Overlocker

What Is An Overlocker
  • Are you buoyant enough? Getting an overlocker can be quite expensive. The minimum you can get for a high-quality overlocker from a well-known brand is £300. That’s not to say, there aren’t cheaper ones available on the market. But keep in mind that buying a cheap overlocker from local supermarkets would only end up frustrating you. So why go through the hassle?
  • Do you have the patience to learn how to use it? It’s one thing to buy an overlocker, and it’s another thing to invest time and patience into learning how to use it efficiently. Most people avoid using their overlocker because of the time it takes to thread. Note that you have to thread each thread individually, and they all have their tension control. You need to do this accurately to get an elegant stitch. It’s also likely that with each different fabric you sew, you would go through the process all over again.
  • Are you a professional? Not trying to discourage you, but you need to be able to sew confidently to use an overlocker. You wouldn’t want to be in a situation where you make a mistake with an overlocker, because its stitches can take forever to unpick.

Parts of and Overlocker

For those interested in sergers, let’s simplify it a bit. Imagine your serger as a handy tool with a few key parts. At the top, there’s a pole with a rod that guides the thread through holes, making sure it’s neat and orderly. The thread then sits on spool pins, with little dials to adjust how tight or loose each thread is.

Your serger also has a presser foot to hold your fabric in place while sewing, and some models have a lever to lift this foot up and down. On the side, there’s a sharp blade for cutting fabric as you go. And, if you ever wonder where those trimmed bits of fabric end up, some sergers have a little box to catch them, keeping everything tidy.

Below is a diagram that outlines all parts on an overlocker.

Parts Of An Overlocker Diagram
Parts of an Overlocker Diagram

Things to consider when buying an Overlocker

There are so many overlockers in the market, so it is very easy to make a mistake when getting one. It can be quite confusing and frustrating to get the right one, but you can make the right choice. Here is how;

Threading difficulty

When you go to purchase any overlocker, pay close attention to how you are shown to thread. The lower looper is where the challenge and nightmare lies. Also, if the salesperson doesn’t want you to try it out for yourself there, you should go somewhere else to buy. Because you would most likely have issues when threading it at home.

Built-in blade

The importance of this cannot be over-emphasized. Not just any kind of blade, the high-quality blade you can sharpen and disengage quickly. Do not buy if the overlocker doesn’t have a built-in blade. Ensure it is relatively easy to use and can cut easily through thick fabrics.


We are back to this again. If you aren’t ready financially, do not buy an overlocker. The cost of an overlocker is its most important factor. Get the best quality your money can offer. Even if you don’t end up using all the stitches for a start, as you progress in your sewing journey, it will come in handy. With time you may want to do a different kind of stitching. So, if you buy an overlocker which you don’t like, and end up wanting to resale, the price would be a fraction of the value you purchased it.

Built-in rolled hem

Most machines these days operate in an efficient manner where you can activate the rolled hem stitch with just a simple twist. There are some overlockers where you need to change the needle plate and foot before doing a rolled hem. These are best avoided.

Positioning of Needles

There are many overlockers in the market that have slanted needle positions. If you do your findings well, you will find one with a vertical needle position. This is preferable because they can penetrate thick fabrics properly and reduce needle breakage.

Differential feed

This is also an important feature in an overlocker. It allows you to sew a wide range of fabrics. Ensure that the overlocker has a 2 to 1 differential ratio and make sure the salesperson shows it to you, including the hem proof.

Thread cutter

Having a thread cutter in the right position would save you time and give you better access when sewing.

Tension problem

We all know this is where the problem lies with using an overlocker. Generally speaking, you get the type of stitch you get depends on the quality of the overlocker. Nowadays, overlockers with Automatic Thread Delivery allow you to create the perfect switch in just one flick of a dial.

Other features to look out for

  • Ensure it has a nice and smooth sound when in use.
  • Before getting an overlocker, make sure it has narrow tubes and a free arm for sleeves
  • An adjustable sewing speed like that of your sewing machine, where the more the push your foot down, the more you sew.
  • Adjustable stitch width and length
  • A seam gauge, whether built-in or removable, to ensure that the fabric can be cut and sewn without stop.
  • Check if it is easy to open either for cleaning or threading
  • Accessories like screwdrivers, tweezers, spool cap, dust cover, and spool net
  • Check to see if each needle is secured by its screw because if not, it would most likely fall inside the overlocker when you want to change it.
  • Removable 2 different width stitch fingers


Hopefully this post has clear up what an overlocker is and why you might need one. If you end up deciding to buy an overlocker, ask your dealer for any demonstration any features and functions you are confused about. I hope you make good use of our suggestions and if you are looking for a really good overlocker see our post What Are The Best Overlockers. We also have an in depth guide on the Best Overlockers For Beginners if you want to start with an easier machine.

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