How to Choose a Serger or Coverstitch Machine

Serger vs Overlocker vs Coverstitch Machine

Three odd names, two different uses. Let’s quickly go over them and see how each of these machines can help us with our sewing projects.

What is a Serger or an Overlock Machine?

The term “serger” tends to be used more in North America than in other parts of the world, and, occasionally, you will hear someone refer to them as “merrow” machines as well. Why? Because Merrow is a brand name for the company who made the first overlock machines, and as a result, it caught on in some circles as a generic term for any overlock machine.

Serger vs Overlock sewing machine

Serger and Overlock machines are one and the same – these are just two different terms for the same machine.

A serger, or overlock machine, basically sews over the edge of a piece of fabric, binding the raw edge with thread through the use of a combination of needles and looping mechanisms. This keeps the edge of the fabric from raveling, and can sometimes act as the hem for a garment.

Serger machines can also be used to seam two pieces of fabric together, binding the raw edges as it stitches. Most serger machines can also trim away any excess fabric from the edge of the stitching with a specialized blade.

The number of needles and loopers on machines vary, depending on the different functions the machine is to be used for, and they can be used on either woven or knit fabrics.

Read more about:

  • Best Serger Machines

What is a Coverstitch Machine?

Serger vs Coverstitch

Coverstitch machines use a combination of needles and a single looper to stitch seams or hems, and are particularly useful on knit fabrics. Their multiple needles work together to stitch a straight stitch on the top of the fabric, while the looper creates looser chain stitching on the underside of the fabric.

When a coverstitch machine is used, it also binds the raw edge of the fabric so any excess beyond the stitching on the bottom can be cut away without raveling. They do not have an attached blade for this purpose like most overlock machines do, however.

Used on most knit hems – look at the bottom of your t-shirt for an example -, coverstitch machines can usually be adjusted to accommodate a variety of stitch widths. Depending on the settings, it can also be used to add trim, such as lace, to a project. Coverstitch machines can also be used to make flat seams on knitwear without bulky seam allowance on the inside of a garment. If you need a simpler stitch, a one-needle coverstitch can also make a simple chainstitch for a decorative and relatively secure stitch option.

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  • Best Coverstitch Machines

Hybrid Combination Machines

Sergers with Coverstitch option

There are machines that can do the work of both a serger and a coverstitch.

They usually involve a bit of fiddling to convert them from one function to another, however, so keep that in mind when looking at this option. If you usually need to switch relatively quickly back and forth from an overlock machine to a coverstitch, you may be better off buying two separate machines just to save the time and trouble of converting one machine back and forth.

Also, hybrid machines do not have a free arm feature, so if you do a lot of coverstitching in the round on sleeve or garment hems, this may not be the best choice for your needs. However, if you regularly have projects that need the functions of only an overlock or coverstitch at one time, you might consider getting a serger with coverstitch to save the cost or space of buying two separate ones.

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  1. Serger vs Overlock vs Coverstitch
  2. How to choose a Serger or Coverstitch?
  3. Features to consider

How to choose a serger or a coverstitch machine?

Before choosing an overlock or coverstitch machine, first think about what tasks you need your machine to accomplish. There are so many bells and whistles available on these machines that it can be quite daunting to choose the features you need.

Before rushing out to buy the fanciest, most expensive model, take stock of what you actually need your machine for.


One of the most common uses of a serger or overlock machine is to finish the raw edge of a piece of fabric so that it won’t ravel.

If you are comfortable sewing most of your projects with a regular machine and just need the edges of the seam allowance contained neatly, a very simple overlock machine may be all that you need. Some come with width adjustments for your edging needs or blades that can move out of the way should you not want the cutting feature.

By adjusting your stitch length on an overlock, you can create a looser stitch that is sufficient for fabrics that aren’t really prone to ravel in the first place, or making a tighter, sturdier edge for fabric that wants to shred all over the place after being cut.


Both overlock and coverstitch machines can help in construction of your projects, depending on what type of seams you’re in need of.

Let’s go over the differences.

Serger machines can seam together both woven and knit fabrics. With a double needle option, a serger machine can seam either woven or knit fabrics together and finish off the seam allowance in one fell swoop. A blade attachment – standard on most overlock machines – cuts away any excess fabric, making for a neat and tiny finished seam allowance. While one needle models are sufficient for binding a raw edge on an overlock machine, it isn’t strong enough to be used to make a seam – without the extra row of stitching on a second needle, the stitching will come apart with any tension on your seam.

Some overlock machines also have the option to move the blade out of the way so you have more control on how wide your seam allowance will be. This is helpful if you think you may need to alter your seam allowance at a later time.

Seaming fabrics with a coverstitch machine is a bit different than using a standard or an overlock machine.

Instead of putting fabric right sides together to stitch your seams, you overlap your fabrics with right sides of both facing up on a coverstitch. The seam is then stitched with the fabric flat.

Some machines have the capacity to bind edges on both the top and bottom layers, so that any excess seam allowance on top and on bottom can be trimmed away. Most domestic machines, however, have only straight stitching options for the top layer – in this case, your top fabric may need to be folded back first to keep the edge from fraying. Either way, this makes for a super-flat seam that is useful for things like activewear, when you may not want a lot of bulky seam allowance on the inside of a garment.

Another option for seaming with a coverstitch is using a single needle to create a simple chainstitch with the looper on the bottom. This is a simple more conventional-looking seam, but if part of the chainstitch breaks at any time during use of the garment or project, the whole seam can unravel. As a result, use caution when deciding to use a simple chainstitch with your coverstitch machine.


Hemming knitwear can be especially tricky when you’re working with the limitations of a regular sewing machine. But with the help of a serger and coverstitch machines, it can be made much easier. This is true for some projects in woven fabrics as well.

The easiest option to finish the raw edge of a woven hem is simply to overlock the hem edge and use this as your finished hem. While not the most decorative finish, it will keep the edges from raveling. If you wish to make a sturdier hem than a simple overlocked edge, you can always turn up your hem allowance after it’s been overlocked and stitch it with a regular machine. Some serger machines also have a rolled-hem option. For a project that needs a hem that doesn’t get turned up, but still needs to look nice, this can be a great feature. A special attachment rolls the edge of the hem over as it’s being overlocked, making for a neat finished edge.

For knit fabrics, a coverstitch machine is a game-changer for hems. A coverstitch hem allows your knit fabric to stretch as it’s being sewn and while it’s in use – no more broken hem threads or struggles with a double-needle setup on a straight stitch machine. Depending on the needle options available, you can create narrower or wider hemstitching, and some models have up to three top needles for a really sturdy stitch. If you know you will only need moderately sturdy hems, you may consider getting a slightly less-expensive three thread model (only two top needles and one bottom looper) instead of the three needle. Also, a coverstitch machine with a free arm option excels at hemming in the round, so you can complete the construction of your project first and easily hem a sleeve or a bottom edge that’s already in a tube shape. Without the free arm, stitching in the round is much more difficult.

Jump straight to:

  1. Serger vs Overlock vs Coverstitch
  2. How to choose a Serger or Coverstitch?
  3. Features to consider

Some additional features to consider:

Differential Feed

Differential Feed helps regulate the way that the top and bottom fabrics are fed through the machine when you’re using more than one layer.

Having a machine with differential feed is particularly useful if you are seaming together fabrics that are of different weights, or if you are stitching together a woven fabric to a knit, for example. With the differential feed control, you can slow down or speed up the rate that the feed dogs on the bottom feed the fabric through the machine. This can compensate for a fabric that wants to feed through the machine at a different speed than the top fabric.

When this feature is not available, it is more difficult to keep the fabrics from stretching or feeding through unevenly, which can lead to unwanted pleats or stretching in your seams.

Differential feed can also be used to create decorative edging in conjunction with an overlock stitch – with the settings adjusted, it can create a purposefully rippled effect to an edge (sometimes called “lettucing” because it resembles the edge of curly lettuces).


While this is not as much the case for most coverstitch machines due to their single loopers, some serger machines in particular can be notoriously hard to thread. A standard overlock machine has two or three loopers which often require color diagrams and special tools to thread them properly.

If you know this is going to be a difficult feat for you, you may want to seek out a machine that features easy threading. Some models of both serger and coverstitch machines have air-powered systems that aid in threading.


One special feature available on some coverstitch machines is a binder.

If you’re stitching a lot of knitwear that needs bound necklines or sleeve edges, such as those on the necks of t-shirts, this may be an attachment option you want to consider. However, these can be expensive and take a bit of practice to master.

If you only do binding some of the time, you may be better off stitching your binding on with an overlock, then turning it and finishing it with topstitching.

Adjustable Presser Foot Pressure

Many sergers and coverstitch machines have a mechanism to adjust the pressure of the presser foot on the fabric. This is a helpful feature if you want a little bit of extra control. You can ease the pressure while stitching over bulky seams, or adjust it between projects if you deal with many different weights of fabric regularly.

Along with a good differential feed setting, it can help make your stitching cleaner even if you’re dealing with variations in thickness on a seam or a hem.

Special Feet

Depending on how you need to use your machine, there are a myriad of special foot options available.

Coverstitch machines, for example, often have a clear foot option, so you can see where your previous stitching lines were when stitching in the round.

Serger machines have feet for stitching in elastic, cording, sequins, or gathering your fabric, among other things.

If you’re not sure which fancy feet you may need for future projects, it’s often possible to purchase a model that will accommodate them later but save the cost of buying all of the gizmos with the machine initially. So it’s worth looking at the optional accessories available to a particular machine model even if you don’t know yet what your projects will require.

Read again:

  1. Serger vs Overlock vs Coverstitch
  2. How to choose a Serger or Coverstitch?
  3. Features to consider

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