If you are new, make sure to check out the Learn to Serge home page. It links to other helpful articles like Meet your Machine, Tension tips, as well as Tips and Tricks. Now let’s review the serger dictionary (I put it in alphabetical order).

serger dictionary

Some sergers convert to a coverstitch machine. This is a really neat feature, but it can take a lot of practice converting it back and forth between the serger function and the coverstitch function. The coverstitch function within the serger create the professional “hemmed” look.  It hems the fabric as well as overlocks the thread underneath the double stitch threads.

To see an example of this, look at the hem of the shirt you are wearing. On the top, you see two stitches (a double needle), on the bottom it looks like a serger stitch. To create this look in one step, you need a coverstitch machine.

You can also create this look by simply serging the raw edge of your project, then fold over and top stitch with a double needle on your sewing machine.  We will actually do this technique in one of our projects within the Learn to Serge series. 

Differential Feed:
Under the presser foot, you will see your feed dogs (it’s the same concept as your sewing machine). However, unlike a sewing machine which has one set of feed dogs, most sergers will have two feed dogs. This allows you to serge fabric at different rates. 

At a normal ratio setting (of 1) the two feed dogs move at the same speed. 

At it’s highest setting (of 2) the front feed dog moves twice as fast as the rear. This will create the fabric to bunch or gather. This setting prevents stretchy materials from stretching too much or from puckering.

At it’s lowest setting (.75) this means the front feed dog will move slower than the rear. This stretches the fabric as it is sewn. This prevents thin materials from puckering.

Differential Feed definition

Knife Release:
The knife release is another way of saying, turn on or off the blades. There are two blades or knives on a serger. An upper and lower knife. The lower knife always stays in place, the upper knife is the blade that moves in sync with the needles. 

The knife release is found on the side of your machine. Usually, it’s like an “on” “off” switch. To turn my upper knife off, I turn the knife lever towards the back of the machine. 

Not only does the upper blade move up and down to cut the fabric, but it also moves closer or farther away from the needle plate. You can adjust the horizontal position of the blade by changing the stitch width. 

knife release definition

Just like a dryer, your serger can build up lint. Why is ‘lint’ in the serger dictionary? I would say this is the second most common reason your serger isn’t working. (The first, it was threaded improperly). To maintain the lint, make sure you clean your serger every 5 – 10 hours of serging time. 

lint buildup

Overlock Machine: 
That is actually the correct name for a “serger” machine. Overlock and Serger are interchangeable words.

A type of sewing machine that cuts the fabric as it overlocks the raw edges with a V-shaped stitch. Some serger machines are three needles, some are four. 

Stitch Length:
This is found on the side of the serger and is used to change the stitch length. The higher the number, the longer the stitches will be apart. The shorter the number, the closer the stitches will be. 

Normal stitch length is between 2.5 and 3 mm for my particular serger. 

stitch length definition

Stitch Width:
The stitch width is found on the side of the serger. The purpose of the stitch width is to change how wide the stitches are. By increasing the number, the stitch width decreases in size (Size 7 is the highest number on my serger. If I set my stitch width to a 7, the stitch width would be the in the most narrow setting). 

By decreasing the number, the stitch width increases. (size 4.5 is the lowest setting, that would make it the widest stitch length for my serger). 

The normal setting is 5 (mm).

stitch width definition

Tension refers to how tight the 4 spools of thread are being pulled. There is a tension dial, or disk, associated with every spool of thread. tension definition

The correct thread tension will vary with each type and thickness of the fabric you are sewing. However, for most projects, you will stay around “home”. For my serger, that number is 4. To read more about when to adjust thread tension, read here

The concept is simple, The higher the tension dial, the tighter the tension.

The lower the tension dial, the looser the tension.  


Keep in mind this serger dictionary is a work in progress. Please let me know what words/concepts/phrases you want to be defined, I will be sure to add them here! 



Learn to Serge Series is the best way to learn how to serge! 12 awesome lessons to reduce your fear of the serger overlock machine!

HERE is another great resource on serging phrases!

Since the Learn to Serge Series has been so popular, I have put all of the lessons in one easy-to-read ebook.  Click here to have all 12 comprehensive lessons at your fingertips! Add to Cart