Confused about serger vs overlock vs coverstitch machines? You’re not alone! First, let’s clear something up: “serger” and “overlocker” are actually the same machine—just different names. In America, we call it a serger, while in the UK and Australia, it’s known as an overlocker.
Although these specialized machines might look similar at first glance, they serve different purposes in your sewing projects. The difference between overlock and serger machines doesn’t exist—they’re identical—but the difference between serger and coverstitch machines is significant. While sergers use between 3 to 8 spools of thread and have loopers that create knit-like stitches, coverstitch machines are designed specifically for creating professional hems, especially on stretchy fabrics[-3]. Additionally, overlock machines trim excess fabric with a blade as they stitch, but coverstitch machines don’t cut fabric at all.
In this guide, we’ll break down exactly how these machines work, when to use each one, and why you might want to add them to your sewing setup. By the time you finish reading, you’ll know exactly which machine is right for your next project.
Key Differences At A Glance
| Feature | Serger/Overlock | Coverstitch |
|---|---|---|
| Thread Count | 3-8 threads | 1-3 threads |
| Loopers | 2 loopers | 1 looper |
| Cutting Blade | Yes – cuts fabric while sewing | No cutting blade |
| Stitch Type | Overlock stitch that wraps around edges | Straight lines on top, chain-like underneath |
| Main Uses | • Seam finishing • Raw edge finishing • Basic construction • Creating ruffles • Gathering | • Hemming • Attaching elastic • Decorative topstitching • Finishing necklines |
| Best For | Both knit and woven fabrics | Primarily stretchy/knit fabrics |
| Stitch Appearance | Similar on both sides | Different on top and bottom |
| Threading Order | 1. Upper looper 2. Lower looper 3. Right needle 4. Left needle | Simpler threading with one looper |
| Stretch Capability | Creates stretchy seams | Creates stretchy hems that recover |
| Fabric Trimming | Yes, trims while sewing | No trimming capability |
What is a Serger, Overlock, and Coverstitch Machine?
Let’s explore what these machines really are and how they differ. Understanding these differences will help you choose the right tool for your project.
Serger vs Overlock: Are They the Same?
The simple answer is yes—serger and overlocker are two names for the identical machine. Americans typically call it a serger, while people in the UK and Australia refer to it as an overlocker. This machine uses multiple threads to create a stitch that resembles knitting more than traditional sewing.
A serger trims and binds seams to the fabric itself to prevent unraveling. It uses two loopers and requires threading through three or four pathways. Most importantly, sergers have knives that cut the fabric edge as they sew, giving you a clean, professional finish on garment seams.
Coverstitch Machine: Purpose and Stitch Type
Unlike a serger, a coverstitch machine is mainly a finishing tool designed for creating professional-looking hems, particularly on stretchy fabrics. It creates a unique stitch with straight lines on top and a chain-like stitch underneath.
What makes coverstitching special is that it creates stretchy seams that won’t break when the fabric is pulled. This machine excels at:
- Hemming knit garments beautifully
- Attaching lace, elastic, or trim quickly
- Creating decorative stitches
A coverstitch machine typically has only one looper (compared to a serger’s two) and has no cutting knives. You can use one, two, or three needles depending on the look you want.
How Each Machine Complements a Sewing Machine
Neither a serger nor a coverstitch machine replaces your regular sewing machine. Instead, they handle specific tasks that standard machines struggle with.
Your regular sewing machine remains essential for most construction tasks, straight stitching, and general sewing projects. A serger adds professional seam finishing and works wonderfully with knits due to its naturally stretchy stitches. Meanwhile, a coverstitch machine completes your setup by providing those perfect professional hems on t-shirts and other stretchy garments.
For the most complete sewing setup, many serious sewists eventually own all three machines. However, if space or budget is limited, you might consider a combination serger/coverstitch machine, though many professionals prefer separate dedicated machines.
Core Functional Differences Explained
Now that we know what these machines are, let’s look at their key differences in how they work.
Thread Count and Looper Setup: 3-8 Threads vs 1 Looper
The number of threads and looper setup is a major difference between these machines. Sergers typically use 3-8 threads and have two loopers, while coverstitch machines use just one looper. Most home sergers can sew with 2-4 threads, but premium models can handle up to 8 threads for more complex stitches.
Order matters when threading a serger: always thread in this sequence – upper looper first, lower looper second, right needle third, left needle last. The lower looper is often the trickiest part to thread.
In contrast, a coverstitch machine has a simpler setup with just one looper underneath. This machine can use 1-3 needles depending on the look you want:
- One needle creates a simple chain stitch
- Two needles produce the classic t-shirt hem look
- Three needles offer maximum strength and stretch
Blade Functionality: Cutting vs Non-Cutting Machines
A key functional difference is that sergers have cutting blades while coverstitch machines don’t. Every serger has at least one blade that trims fabric edges as you sew. This creates clean, professional-looking seams in one step.
Coverstitch machines have no cutting blades at all. They don’t trim fabric as they sew, since their primary purpose is hemming and topstitching, not edge finishing.
Stitch Type: Overlock vs Chainstitch vs Coverstitch
Sergers create overlock stitches that wrap threads around the edge of fabric. These stitches look similar on both sides of the fabric and prevent fraying.
Coverstitch machines create two distinct sides: straight parallel stitches on top and a chain-like pattern underneath. A chain stitch is formed when needle thread passes through material and interloops with one looper thread. This gives knit fabrics the stretch they need without breaking.
Fabric Handling: Stretchy Knits vs Woven Fabrics
Both machines handle different fabric types, but they shine with knits. Knit fabrics are made by interlocking yarn with long needles, creating a stretchy material perfect for t-shirts and leggings. Woven fabrics have a rigid structure from interlaced vertical and horizontal threads.
Sergers work well with both knits and wovens, yet they’re especially valuable for knits because their stitches stretch naturally with the fabric. Coverstitch machines are designed specifically for stretchy fabrics, creating hems that can stretch and recover without breaking stitches.
For knit fabrics, these specialized machines beat regular sewing machines because knits need stitches that can stretch along with them.
Use Cases and Best Applications
Each specialized machine has its sweet spot in the sewing world. Knowing when to use each one will make your projects look store-bought rather than homemade.
When to Use a Serger: Seam Finishing and Construction
Sergers excel as multitaskers that sew, trim, and finish all at once. They’re your go-to for:
- Finishing raw edges to prevent fraying
- Creating clean, professional seams
- Sewing stretchy knit fabrics that regular machines struggle with
- Adding ruffles and soft gathering to garments
A serger wraps threads around fabric edges, making it perfect for construction areas that need to withstand stress and movement, such as side seams on fitted garments. For formal menswear, a 2-thread overlock creates lightweight seam finishes on woven fabrics. When working with knits, a 4-thread overlock provides both strength and flexibility.
When to Use a Coverstitch: Hems, Trims, and Elastic
Unlike sergers, coverstitch machines are specialists focused on creating professional finishes. Reach for your coverstitch when:
- Hemming sleeves, pants, or t-shirt bottoms
- Attaching elastic to undergarments
- Adding decorative topstitching
- Finishing necklines with a stretchy finish
Coverstitch creates that double or triple row of parallel stitches on top with a zigzag underneath—exactly what you see on store-bought t-shirts. It’s also remarkably helpful for attaching lingerie elastics with a durable, professional finish.
Overlock vs Coverstitch in Activewear and Knitwear
For activewear and knitwear, these machines play different roles. Sergers handle construction while coverstitch machines create those perfect hems. Most high-street sweatshirts are manufactured using coverstitch machines from start to finish.
Overlock stitches excel at seam strength under pressure, whereas coverstitch excels at creating stretchy, good-looking hems. For complete activewear projects, many sewers use both machines—serger for construction, coverstitch for the polished look.
Decorative Stitching and Utility Stitching
Beyond basic functions, both machines offer creative possibilities. Coverstitch can be used with contrasting thread colors for decorative effects. You can also use narrow or wide needle placement for different looks.
For utility purposes, sergers create strong, reliable seams. The 5-thread overlock (safety stitch) works wonderfully on heavier fabrics, adding chainstitching alongside the seam. Moreover, chain stitches can secure beltloops, create decorative jeans hems, or quickly baste muslins.
Combo Machines vs Separate Units
For sewers with limited space or budget, combo serger/coverstitch machines offer an appealing option. These versatile devices perform both functions in a single unit, potentially saving you money and precious workspace.
Pros of Combo Serger/Coverstitch Machines
Combo machines shine in several ways:
- Space efficiency – perfect for small sewing rooms where multiple machines wouldn’t fit
- Cost savings – generally less expensive than buying two separate machines
- Versatility – can perform overlocking, coverstitching, and chainstitching
- Budget-friendly – good for beginners who want both capabilities without a large investment
Some combo machines offer excellent features like air threading and can handle 2-5 threads depending on the model.
Limitations of Combo Models: No Free Arm, Setup Time
Despite their advantages, combo machines have notable drawbacks. First, most combo models lack a free arm, which makes hemming sleeves and pant legs much harder. Furthermore, converting between serging and coverstitching functions typically requires reconfiguration—changing needles, throat plates, and threading patterns—which can take 5+ minutes each time.
This reconfiguration process often feels tedious when switching frequently between functions during a single project. For instance, serging a shoulder seam, then coverstitching a neckline, then returning to serging another seam requires two conversions.
Why Professionals Prefer Separate Machines
Professional sewers typically choose separate machines for several reasons. Primarily, having dedicated machines means each is always set up and ready to use, eliminating conversion time. Consequently, you can move seamlessly between machines as needed.
Additionally, separate machines typically perform their specific functions better than combo models. Many professionals find that dedicated machines produce more perfect overlock and coverstitch results.
Finally, there’s the reliability factor—if a combo machine breaks down, you lose both functions at once. With separate machines, a problem with one doesn’t affect your ability to use the other.
Conclusion
Understanding the differences between serger, overlock, and coverstitch machines can save you time and frustration with your sewing projects. First of all, remember that sergers and overlock machines are actually the same thing—just called different names depending on where you live. They excel at creating strong, neat seams while trimming excess fabric at the same time.
Coverstitch machines, however, serve a completely different purpose. They make those professional-looking hems you see on store-bought t-shirts and activewear. Unlike sergers, they don’t cut fabric but instead create stretchy stitches that won’t snap when pulled.
The right machine for you depends on what you sew most often. If you work mainly with seam construction and finishing raw edges, a serger will be your best friend. But if you make lots of knit garments and want those perfect stretchy hems, a coverstitch machine is worth considering.
