Sergers

Overlock: What It Means in Sewing

Three things "overlock" can mean, at a glance

• The machine, short for overlocker, the UK/Australian name for a serger. See Overlock vs. Serger for the regional-naming breakdown.
• The stitch, the looped thread pattern that trims and wraps a fabric edge. See Overlock Stitch for how it's made and how it differs from a sewing machine's imitation setting.
• The finished seam, a garment described as "overlocked" has had its seam allowances trimmed and edge-finished by a serger, which is the standard finish on most ready-to-wear knit clothing.

Sewing often uses one root word for a machine, a technique and a result. Overlock is one of the clearest cases. Once you know all three meanings exist, the context almost always tells you which one a sentence means. That holds for a shop listing, a pattern step or a care label.

Why it matters practically

Say a pattern, a video or a manual tells you to "overlock the seam allowance." It means: trim and finish that raw edge with a serger, or the closest sewing machine stand-in. See Serger vs. Sewing Machine for what that stand-in looks like if you don't own a serger yet. It is a step about the finish, not a brand or a model. You don't need any one machine to follow it, as long as the edge ends up trimmed and covered.

Where the word shows up on packaging and listings

Stores and makers use "overlock" in a few paired terms worth knowing. An "overlock machine" is the serger itself. An "overlock foot" is a special sewing machine foot that helps copy the stitch.

"Overlock thread" is cone thread made for the amount a serger uses. An "overlock function" or "overlock stitch setting" is the look-alike stitch on many sewing machines. Knowing these terms stops you from treating each one as a strange new product when you compare listings.

How this shows up in seam construction terminology, in practice

Patterns sometimes use "overlock" as a verb: "overlock the raw edges before assembly." Sometimes they use it as a noun for the finish: "finish with an overlock." Either way, it points to the same step. You trim and wrap the cut edge so it survives handling and washing without fraying. If a pattern names no finish at all, overlocking is a safe default. Use it, or the sewing machine stand-in, on any seam edge that will stay open inside the garment and not be covered by a lining or facing.

A short glossary of related terms

• Overlocker: the machine, UK/Australian naming.
• Serger: the machine, US naming.
• Overlock stitch: the stitch pattern the machine produces.
• Overlocked seam: a seam that has been trimmed and finished with that stitch.
• Overlock foot: a specialty sewing-machine presser foot that helps approximate the stitch without a serger.
• 2/3/4-thread overlock: stitch variations distinguished by how many threads are used, not different machines.

Keep this list in mind. It makes new product listings, forum posts and pattern steps much less confusing. Nearly every use of "overlock" you will see fits one of these six meanings.

A note on how this differs from coverstitch terminology

Take care not to mix up overlock terms with coverstitch terms. People often mention the two stitch families together, but they do different jobs. Overlock trims and finishes a raw edge.

Coverstitch hems a folded edge and trims nothing. See Coverstitch vs. Overlock if a listing uses both terms and you aren't sure which one you need.

Overlock as it appears in fabric care labels

You may also see "overlocked" on care labels or product descriptions for ready-made items. It means a seam or edge was finished this way at the factory. It only describes how the item was made.

It does not change how you wash it beyond what the rest of the label says. We mention it because it is one more place the word shows up outside tutorials and listings. Knowing it saves you from wondering if it says something about fabric care.

Where to go next

If you are still deciding whether you need a machine that does this, start with What Is a Serger?. It covers the case for and against buying one. If you already know you want one, Sergers for Beginners and Best Beginner Overlocker cover the buying choice. Overlocker Sewing Machine breaks down the features worth checking before you buy.