Every machine in the JUKI domestic overlockers range sews 2, 3 and 4-thread stitches. What differs between models is how each one switches to 2-thread.

How Are Overlocker Stitches Named?

By thread count, which is the number of needles plus the number of loopers in use. Loopers take the place of a sewing machine’s bobbin and interlock the threads around the edge, which makes the stitch closer to knitting than to a lockstitch, as New Mexico State University’s overlocker guide explains.

Industry spec sheets sometimes use stitch codes instead of thread counts. These all sit in class 500, the overedge stitches, of the international standard ISO 4915.

On JUKI overlockers, each thread path is colour-coded, so you can trace every thread to its needle or looper. Coming from a household machine? Our comparison of the overlock stitch on a sewing machine shows what an overlocker adds.

What Is a 4-Thread Overlock Stitch Used For?

Seaming. The second needle line adds strength, so a 4-thread overlock suits seams that take strain in both knit and woven garments, according to the New Mexico State University guide. It sews the seam and finishes the edge in one pass.

Use it for T-shirts, leggings and sweatshirts, and for side seams on woven dresses and trousers.

Where it is overkill: finishing an edge on its own. University of Kentucky Cooperative Extension’s seam finishing guide calls 4-thread unnecessary for edge finishes because it only adds bulk; a 2 or 3-thread stitch does the job.

3-Thread Overlock: Wide or Narrow?

Take out one needle. Keep the left needle for a wide stitch or the right needle for a narrow one; JUKI’s specifications describe the same choice.

A 3-thread overlock has more give than a 4-thread, so the University of Kentucky guide recommends it for knit seams where stretch matters more than strength. It is also the everyday edge finish for woven seam allowances.

Keep it away from seams under heavy strain, such as a trouser crotch or a sleeve seam (New Mexico State University). The same stitch is the base for the rolled hem and flatlock.

2-Thread Overlock: When Do You Need It?

For the lightest edge finish on fine fabrics. One needle thread and the lower looper thread wrap the edge, while a converter closes off the upper looper. It leaves the least bulk of any overlock stitch, but it is a finish rather than a seam: keep it away from anything that takes strain (New Mexico State University).

Use it on voile, chiffon and lightweight cotton seam allowances, and on scarf and napkin edges.

If 2-thread matters to you, check how a model handles it before you buy. Not every 3 and 4-thread overlocker converts to 2-thread.

Which JUKI Overlockers Sew 2-Thread?

Flatlock and Rolled Hem: Same Threads, Different Settings

Both are 2 or 3-thread stitches with the tensions changed, rather than separate stitch types.

Flatlock

Loosen the needle thread and the seam pulls open to lie flat, with loops on one side and a ladder on the other. Either side can face out. Flatlock suits activewear, fleece and sweatshirts, where a seam ridge would rub.

Rolled Hem

The edge rolls under as it is stitched and is wrapped in thread, giving a narrow finish for scarves, napkins and fine fabrics. On JUKI overlockers with automatic rolled hemming, you switch with a lever, with no change of foot or needle plate. On stretch fabric, combine it with differential feed for a frilled “lettuce” edge; JUKI lists a frill 3-thread rolled hem among the MO-2000QVP’s stitches.

One stitch an overlocker does not sew is the hem with two parallel rows of stitching on top, seen on most T-shirts. That is a coverstitch, made on a coverstitch machine.

Which Overlocker Settings Trip People Up?

• The converter left in place. If the 2-thread converter is still fitted when you switch back to 3 or 4-thread, the upper looper cannot form its part of the stitch. Remove or disengage it first.
• Wavy jersey treated as a tension problem. A wavy edge on knits usually comes from the feed. Raise the differential feed above its neutral setting so the front feed dogs ease more fabric in, before you touch the tensions.
• The rolled hem setting left on. If a standard overlock comes out narrow and rolled, check the rolled hem lever before changing anything else.

Which Overlocker Stitch Should You Use?

Most projects need two: a 4-thread overlock for seams and a 3-thread overlock for finishing edges. The rest are for specific fabrics and finishes.

If you would rather not thread the loopers by hand, the MO-2500 Sumato threads them with air. Add specialist feet from the overlocker feet and accessories range for techniques such as gathering, piping and elastic. For the full range of machines and stockists, visit JUKI UK.

The post Overlocker Stitch Types Explained: 2, 3 and 4-Thread Stitches and When To Use Each appeared first on Juki UK Sewing Machines.

Every JUKI household machine sews a convincing overlock-style stitch, because the precision and feed system behind the straight stitch drive the overedge stitches too. That covers each JUKI electronic sewing machine in the range. The one exception is the straight-stitch TL range.

What Is the Overlock Stitch on a Sewing Machine?

It is an overedge stitch. The needle swings to the right, just past the raw edge, then back into the fabric, so the thread wraps the edge instead of sitting beside it. The finish imitates an overlocker using only the needle thread and the bobbin thread.

That is also the main technical difference. An overlocker forms its stitch with loopers instead of a bobbin, and that stitch has its own family (class 500, overedge chain stitches) in the international stitch classification, ISO 4915. The household version is a variation of the lockstitch your machine sews for everything else.

Stitch names vary between models, but most stitch charts include three types:

• Overcast stitch: a single row of stitches wrapping the edge, for light and medium fabrics.
• Double overedge: two rows sewn together, for fabrics that fray heavily, such as linen.
• Overlock-style stitch: a straight stitch combined with wrapping stitches, the closest in look to an overlocker.

Your manual shows which of these are designed for the overcasting foot.

On the HZL-DX7, the overlock stitches sit among 287 stitch patterns. They are fed by JUKI’s box feed, a system taken from JUKI’s industrial machines that moves the fabric evenly under the foot, which is what lets the stitch form cleanly right at the edge. The TL straight-stitch machines are built for straight stitching only, so they have no overlock stitch.

How Does the Overcasting Foot Work?

The overcasting foot holds a thin metal bar, or finger, right at the fabric edge. The needle swings over that bar on every right-hand stitch, so the thread forms around the bar instead of tightening around the fabric. The edge stays flat rather than drawing up into a hard ridge.

The overcasting foot is included with every JUKI machine, and it works on the same principle as an overlocker. As our team puts it, it uses a bar or “finger” to prevent the fabric from rolling. On an overlocker, the stitch finger on the needle plate does that job.

A guide on the foot keeps the edge running straight, which matters because the foot does not cut. Trim the seam allowance to its finished width first, then overcast it; there is nothing to trim afterwards. University of Kentucky Cooperative Extension’s seam finishing guide gives the same order: trim, then stitch with the overcast presser foot.

One caution: use the stitches your manual pairs with this foot. JUKI’s accessory guidance says the overcasting foot is not for zigzag stitches, because a wide swing can strike the finger. If yours is lost or damaged, the overcasting presser foot is sold separately, alongside the rest of the JUKI sewing machine feet.

Overcasting Foot vs Overlocker: What Changes on Cotton and Jersey?

On woven cotton, the two finishes are close: both stop fraying and both lie flat inside a garment. On jersey, the overlocker pulls ahead, because its seam stretches with the fabric and its differential feed keeps the edge from going wavy.

Woven Cotton

Woven fabric frays but barely stretches, so the stitch has one job: hold the edge. A household overedge stitch does that well, and on a medium-weight cotton the result comes close to an overlocked seam allowance. The difference is mostly in the process. The overlocker trims and finishes in one pass; with the foot, you trim first and stitch second.

Jersey and Other Stretch Fabrics

Here the gap shows. As our team puts it, you can see the difference when using a sewing machine on a stretch fabric. Three things cause it:

1. Stretch. A stitch made from needle and bobbin thread has limited give, so it can snap when the seam is pulled. An overlocker’s looper threads move with the knit.
2. Feed. Without differential feed, a knit edge can stretch out under the foot and finish wavy.
3. The job itself. Jersey does not fray, it curls. A finish on jersey is about stretch and control, which is what an overlocker is built for.

The University of Kentucky guide agrees: it recommends the machine overedge stitch for fraying woven fabrics, not knits.

For knit seams, an overlocker usually sews a 3 or 4-thread stitch; our guide to overlocker stitch types explains which to choose.

When Is the Overcasting Foot the Better Choice?

When the job is small, woven or hidden inside a garment, the foot is often the quicker tool, even for someone who owns an overlocker.

• A single repair or one seam, where re-threading an overlocker would take longer than the sewing.
• Seam allowances on wovens that you will press open, finishing each side separately.
• A thread colour your overlocker is not threaded with.
• Edges you do not want trimmed, such as a seam allowance you may need to let out later.

Plenty of sewers keep both machines for exactly this reason. JUKI ambassador Janet Poole, a quarter-finalist on series 5 of The Great British Sewing Bee, sews on an HZL-DX7 she calls “a workhorse with bells on”, alongside an MO-654DE overlocker.

Do You Need an Overlocker If Your Machine Has an Overlock Stitch?

Not if you mostly sew woven fabrics. If you sew jersey, activewear or knit garments regularly, or want a ready-to-wear finish inside your clothes, an overlocker earns its place.

• Mostly cotton dressmaking, quilting or bags: the overcasting foot covers it.
• Occasional knits: the foot plus a stretch stitch will get you through; expect a less flexible seam.
• Regular jersey, activewear or loungewear: an overlocker saves time and gives stronger, stretchier seams.
• Batch sewing or selling what you make: the overlocker’s one-pass finish makes the bigger difference.

The JUKI domestic overlockers range runs from models with colour-coded threading to air-threading machines. The MO-654DEN, the current version of the overlocker Janet uses, sews 2, 3 and 4-thread stitches with built-in rolled hemming. For the full range of machines, feet and stockists, visit JUKI UK.

The post Overlock Stitch on a Sewing Machine: How Close Can the Overcasting Foot Get? appeared first on Juki UK Sewing Machines.

What Does a Sewing Machine Do That an Overlocker Cannot?

Anything that happens away from the raw edge or needs a precise stop and start. Zips, buttonholes, topstitching, darts, pockets and quilting are all sewing machine jobs.

The HZL-DX7 shows how much of this one household machine carries. It has 287 stitch patterns including 16 buttonhole styles, a drop feed for free-motion work, and more than 30 needle positions in straight stitch for setting concealed zips and piping. Janet Poole, a quarter-finalist in series 5 of The Great British Sewing Bee, describes her DX7 as a workhorse with bells on and picks out its buttonhole system.

The full range is under JUKI household sewing machines.

What Does an Overlocker Do That a Sewing Machine Cannot?

It trims the seam allowance with a built-in knife and wraps the cut edge in thread in the same pass. The result is a stretchy seam that will not fray, sewn quickly.

A 4-thread overlocker uses two needles and two loopers, one upper and one lower, all fed from cones on a thread stand. The loopers carry thread over and under the fabric edge and interlock with the needle threads, so the edge is enclosed rather than stitched through (how an overlock stitch is formed). The knife sits just ahead of the needles, so every seam allowance comes out the same width.

Differential feed. An overlocker has two sets of feed dogs, one in front of the other, and you can set them to move at different speeds. With the front set moving more, jersey stops stretching out into a wavy seam. With it moving less, lightweight fabric stops puckering. Push the front set further still and the machine gathers the fabric as it sews.

Built-in rolled hem. Domestic overlockers switch to a narrow, tightly rolled edge for chiffon, scarves and frills. On the MO-654DEN, you move a lever on the needle plate and adjust one tension dial. Turn up the differential feed while rolling the edge of a stretch fabric and you get a lettuce-leaf edge.

Compare models in the JUKI domestic overlockers range.

Where Do Overlockers and Sewing Machines Overlap?

Both machines can join a seam and neaten a raw edge. They do it with different stitch structures, though, so the results look and behave differently.

Stitch types are grouped by how their threads interlock in the ISO 4915 stitch types standard. A sewing machine forms a lockstitch (class 300). An overlocker forms an overedge chainstitch (class 500), where looped threads wrap the edge and can extend with the fabric. The overcast stitch on a household machine copies the look of overlocking, but it is still a lockstitch, sewn beside an edge that nothing has trimmed.

Fit the Overcasting Presser Foot to a JUKI HZL-DX, G, H, NX or UX series machine, select the overcast stitch, and it holds the edge while the stitch forms over it. On a lined skirt, or trousers where the seam allowances will never be seen, that is all you need. The edge will not fray and you have not bought a second machine.

Sew a jersey t-shirt side seam the same way and the limits show. The overcast lockstitch has little give, so when the fabric stretches the thread pulls tight or snaps, and thin jersey can tunnel up under the stitch.

Rolled hems are closer. A Rolled Hemming Presser Foot gives a narrow turned-and-stitched hem on a household machine, which suits fabrics where you want a folded hem rather than a thread-wrapped edge..

Why Can’t an Overlocker Hem a T-Shirt?

Because the twin rows of stitching on a shop-bought t-shirt hem are a coverstitch, and a standard overlocker does not sew one.

A hem needs stitching some way up from the fold, through two layers, with nothing cut. A coverstitch machine does that with two or three needles on top and a single looper underneath. The right side shows parallel straight rows, while the looper thread forms a mesh on the wrong side that covers the raw edge and lets the hem stretch.

On a sewing machine, the workaround is a twin needle. It gives the same two rows on the right side, but underneath there is only a single bobbin thread zigzagging between them. On lightweight jersey, expect less stretch and a raised ridge between the rows.

If you hem knits regularly, the MCS-1800 sews a 3, 2 or 1 needle coverstitch with adjustable differential feed. The rest of the range is under coverstitch machines.

Why Do Most Dressmakers End Up Using Both?

Because a garment moves between them. The sewing machine handles construction and details, the overlocker handles knit seams and edge finishing, and many garment sewists add a coverstitch for hems.

Several of JUKI’s ambassadors from The Great British Sewing Bee list exactly that setup:

• Janet Poole (series 5): HZL-DX7, MO-654DE and MCS-1800
• Mercedes Ferrari-Plumridge (series 5): NX7 Kirei, MO-654DE and MCS-1800
• Liz Grylls (2020 series): HZL-UX8, MO-654DE and MCS-1800

Mercedes uses her trio on fabrics from silk chiffon to upholstery-weight coat fabric. Each of the three pairs a computerised household machine with the same overlocker, the MO-654DE, which is a useful real-world reference if you are choosing a pair.

A simple jersey top shows how the work passes between machines:

1. Overlocker: shoulder seams, neckband, sleeves (set in flat) and side seams
2. Sewing machine: topstitching the neckband seam allowance down, plus any buttonholes, tabs or pockets
3. Coverstitch: sleeve and bottom hems (or a twin needle on the sewing machine)

Wovens change the balance, since a sewing machine alone can make a lined dress or tailored trousers from start to finish. For a garment-by-garment answer, see our guide on whether you need an overlocker for the clothes you make.

Which Machine Should You Buy First?

Buy a sewing machine first unless you already own one. Add an overlocker when knits or edge finishing start slowing you down.

• No machine yet: start with a household sewing machine. It does every job an overlocker cannot, and with an overcasting foot it neatens edges until you are ready for more.
• You own a sewing machine and sew mostly jersey or activewear: add an overlocker. The MO-644D is the entry point, with 2/3/4 thread overlocking, differential feed and a built-in rolled hem.
• Hems on knits are the frustration: look at a coverstitch machine before anything else.

Try at a sewing show or through a JUKI stockist before you decide. Machines from JUKI UK come with a 2-year manufacturer’s guarantee and UK-based support.

The post Overlocker vs Sewing Machine: What Each One Does and Where They Overlap appeared first on Juki UK Sewing Machines.

The table below gives a verdict for each type of garment, so you can check it against what you actually sew.

Which Clothes Can You Make Without an Overlocker?

Anything made from non-stretch woven fabric can be finished well on a sewing machine alone. Stretch fabrics are where a sewing machine starts to compromise, because a standard seam has less give than the knit around it and can snap when the garment is pulled on.

If most of what you sew sits in the top half of the table, a good household sewing machine covers everything you need. The finishes it relies on, such as French and flat-felled seams, have been used on quality clothing for far longer than domestic overlockers have existed.

Fine fabrics don’t fit neatly into one row. On silk and chiffon, a French seam sewn on a sewing machine is the classic finish, yet an overlocker’s rolled hem gives a delicate, even edge on a scarf or frill. JUKI ambassador Mercedes Ferrari-Plumridge sews silk chiffon on her JUKI machines, so fine fabric is no reason to rule an overlocker out.

How Do You Finish Seams Without an Overlocker?

Use an overcast or zigzag stitch with an overcasting foot for speed, or enclose the raw edge inside the seam itself with a French or flat-felled seam. Which one to choose depends on the fabric and on whether the inside of the garment will be seen.

Overcast stitch. On most JUKI HZL series machines, the quickest finish is an overcast stitch sewn with the Overcasting Presser Foot. A guide on the foot sits against the raw edge, so the stitch wraps over it instead of pulling the fabric into a ridge underneath, a problem known as tunnelling. The foot fits HZL-DX, G, H, NX and UX series machines.

French seam. Sew the seam with wrong sides together, trim close, then fold and sew again with right sides together so the raw edge is sealed inside. It suits sheer and lightweight wovens, where any edge finish would show through.

Flat-felled seam. One seam allowance is trimmed, the other folded over it and stitched flat, giving a strong seam that looks tidy from both sides. It’s the finish you’ll find on most shirts and jeans.

Bound edge (Hong Kong finish). Each seam allowance is wrapped in a strip of bias binding. It’s slower than the other methods, but it gives an unlined jacket a high-end inside and stops linen and other loose weaves fraying in the wash.

Stretch fabric. Sewing jersey without an overlocker works if the thread can move with the fabric: use a stretch stitch or narrow zigzag and a ballpoint or stretch needle. A walking foot feeds the layers evenly so seams don’t wave. JUKI ambassador Jen Hogg points out that the NX7 Kirei has one built in.

When Does an Overlocker Make Things Worse?

An overlocker makes things worse when it’s used for jobs a sewing machine does better: seaming woven garments on the overlocker alone, trimming seam allowances before you’ve checked the fit, or expecting it to hem a t-shirt.

On woven fabric, a seam sewn only on the overlocker can pull away from the weave under strain, most noticeably at the side seams of fitted trousers and across the back of a jacket. Sew the seam with a straight stitch on your sewing machine first and use the overlocker to neaten it.

The overlocker’s knife also trims the seam allowance as it sews. That’s fine once a garment fits, but it removes the fabric you’d need to let a waist or bust out. Tack or baste, try it on, then overlock.

Finally, a standard overlocker can’t sew the twin-needle stretch hem you see on shop-bought t-shirts. That’s a job for a coverstitch machine. For a fuller picture of what an overlocker can and cannot do, see our comparison of overlockers and sewing machines.

When Is an Overlocker Worth Buying?

An overlocker is worth buying when stretch fabrics are a regular part of what you sew, when finishing edges is the slowest part of your projects, or when you’re selling what you make. Answer these honestly about the last few things you made:

• Most of your projects use jersey, rib or other knits, not an occasional t-shirt.
• You want to make leggings, activewear or swimwear that has to survive stretching and repeated washing.
• You spend longer finishing edges than sewing the seams themselves.
• You sell your makes, and customers will see the inside.

If none of these applies, put the money towards fabric or a presser foot for your sewing machine instead.

If you tick two or more, the MO-644D is JUKI’s entry model, sewing with two, three or four threads and including a built-in rolled hem and differential feed for stretch fabrics. If threading is what puts you off, the MO-1000 Air Threader threads the loopers with a push of air. The full range is on the domestic overlockers page.

A well-finished seam also makes clothes easier to repair, which matters: WRAP’s research on clothing longevity found that repairing clothing extends its life by around 1.3 years.

Threading, stitch quality and noise are easier to judge in person than from a product page, so try a machine before you buy. JUKI UK machines are available to try through UK stockists and at sewing shows around the country.

The post Do You Need an Overlocker To Make Clothes? An Honest Answer by Garment Type appeared first on Juki UK Sewing Machines.