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.