How to Use a Cover Hem Machine for Perfect Stretch Stitches
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Time to read 6 min
Mastering the Cover Hem for Perfect Stitches
If you’ve ever examined the bottom of a T-shirt or the edge of a knit sleeve, you’ve probably seen those two parallel rows of stitching that stretch right along with the fabric. That clean, professional finish comes from a coverstitch machine—one of my favorite tools for sewing with knits.
It’s different from a regular sewing machine or a serger. A coverstitch machine is designed specifically for hemming stretch fabrics, giving you flexible seams that won’t pop. If you’ve been frustrated by broken threads or wavy hems, this might be just what you need.
What is a Cover Hem Machine?
A cover hem machine, more commonly known as a coverstitch machine, is a specialized sewing machine designed for hemming stretchy fabrics like knits, activewear, and T-shirts. It creates two straight lines of stitching on the top and a looper thread underneath, forming a flexible seam that moves with the fabric.
One of the biggest differences between a coverstitch machine and a standard sewing machine is that there’s no bobbin. Instead, it uses a chain looper to form the underside of the stitch, giving you strong, stretchy seams that won’t snap when the fabric stretches. That’s why it’s such a go-to for hemming knit garments.
Here’s a quick checklist to keep in mind:
• Multiple Needles: Most models use two or three needles for different stitch widths.
• Looper System: Creates the chain stitch underneath instead of using a bobbin.
• Differential Feed: Helps control fabric stretch or puckering.
• Presser Foot Guides: Keeps your stitches straight and even.
• No Cutting Blade: Unlike a serger, it doesn’t trim fabric while sewing.
Do You Have The Right Machine to Cover Hem?
Not all sergers are built for cover stitching, so it’s worth checking before you get started. Here’s how I usually tell if a machine can do a cover hem:
1. Thread Count – Most standard sergers have four threads. If that’s all yours has, it probably doesn’t include a cover hem function.
2. Needle Positions – Coverstitch machines have dedicated needle positions for cover hems. The needles on the left side are used for hemming, while the right side is reserved for serging.
3. Threading Options – If your machine has five or more spool pins, there’s a good chance it’s capable of coverstitching. More spools usually mean more functionality.
If you’re unsure, check your manual—or bring your machine into your nearest Quality Sewing location and we’ll help you figure it out.
Getting Your Machine Ready For A Cover Hem
Before you start stitching, there are a few things I always check to make sure my machine is ready for a cover hem.
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1. Set the Needles Correctly
Coverstitch machines have separate needle positions. The right-side needles are typically used for serging, while the left-side needles handle the cover hem. For most projects, I use the far-left and far-right cover hem needles, but always double-check your manual to confirm the correct setup for your machine.
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2. Disengage the Knife
Since a cover hem stitch doesn’t involve trimming fabric, you’ll want to lower or disengage the cutting blade on your machine. This helps avoid accidentally cutting your fabric while sewing.
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3. Adjust Stitch Length and Feed
If your stitches are bunching or the fabric is puckering, the stitch length may be too short. I usually increase the stitch length slightly to get a smooth, even finish. If the fabric starts to stretch while sewing, tweaking the differential feed can make a big difference.
Sewing A Test Stitch
Before I start hemming the real project, I take a moment to test everything on a scrap piece of the same fabric. It’s a simple step that can save a lot of frustration later.
Watch for:
• Smooth, even stitches—no puckering or stretching.
• Enough stretch to pull on and off comfortably.
• Adjust settings if needed for better fabric handling.
Sewing a Hem with a Cover Hem Machine
Once my machine is threaded and the settings are dialed in, it’s time to get the hem ready.
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1. Preparing Your Hem
I turn up the fabric to the length I want and press it well so everything stays in place. If I’m hemming something narrow—like a sleeve or pant leg—I usually turn the garment inside out. That gives me better access and helps keep the stitching even.
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2. Aligning the Fabric
With the hem right side up, I slide it under the presser foot. I rely on the markings on the foot or plate to keep my stitch line straight. Ideally, I want the needles to stitch just past the raw edge of the folded hem, so it catches securely underneath.
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3. Sewing the Cover Hem
To avoid bulk, I try not to start directly on a seam. I’ll begin just before or after, keeping the fabric moving steadily while I follow the guide lines for a consistent finish.
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4. Finishing the Hem Without Unraveling
Coverstitch machines don’t work like a regular sewing machine when it comes to finishing. To safely remove the fabric, I turn the handwheel to lower the needles into the fabric, raise them back up, lift the presser foot, and then gently pull the fabric straight back. That releases the threads from the looper without unraveling the stitches.
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5. Securing the Threads
Once the hem is done, I flip the garment to the wrong side and look for the looper thread. Using a seam ripper or my fingers, I pull it through to the back. Then I either tie off the loose threads or weave them into the seam to keep everything locked in place. That way, the hem holds up wash after wash.
Why Use a Cover Hem Machine?
There’s a reason professional garments look so clean—most of them are finished with a cover hem. The double row of stitching not only looks sharp, but it also stretches with the fabric, making it perfect for everything from basic T-shirts to activewear.
Additional benefits of having a coverstitch machine:
• It gives a polished, professional finish that looks store-bought
• The stitches move with the fabric, so they won’t pop or break when stretched
• It secures hems without leaving raw edges
• It’s quicker and more consistent than using a twin needle on a regular sewing machine
If you’re sewing garments with knits or stretch fabric, this machine really makes a difference. Once you get the hang of it, cover hemming becomes second nature—and it makes your finished projects look and feel better too.
Want pro-looking hems at home? Check out our full lineup of coverstitch machines—perfect for knits, activewear, and T-shirts.
Happy Sewing!
~Reva
Can I use a regular sewing machine for cover hemming?
You can mimic a cover hem stitch with a twin needle on a regular sewing machine, but it won’t have the same stretch or durability. A cover hem machine ensures professional-quality hems without breaking or popping stitches when the fabric stretches.
How do I prevent skipped stitches when using a cover hem machine?
Skipped stitches often happen due to incorrect needle choice or tension settings. Try these solutions:
• Use ballpoint or stretch needles for knit fabrics.
• Ensure your presser foot pressure is adjusted properly.
• Increase needle tension slightly if the stitches are loose.
• Sew at a steady speed—stitching too fast can cause inconsistencies.
What kind of thread works best for cover hem stitching?
For best results, use polyester thread because it has slight stretch and durability. Woolly nylon or textured thread in the looper can enhance flexibility for activewear and knit hems.
Why does my cover hem machine leave tunneling or rippling in the fabric?
Tunneling happens when fabric puckers between the stitches. To fix this:
• Adjust the differential feed to prevent stretching.
• Use a stabilizer or spray starch for lightweight fabrics.
• Lower the needle tension slightly for smoother stitches.
How can I keep track of pins and needles while sewing?
A cover hem machine is perfect for:
• Hemming T-shirts, leggings, and knit dresses.
• Finishing activewear and stretch fabrics without breaking stitches.
• Creating decorative topstitching on casual or performance wear.
