Industrial Sewing Machines in a Garment Factory: The Main Types
A home sewing machine makes one or two stitches, and a garment factory needs a lot more, which is why industrial sewing machines come in so many types. Industrial sewing machines are designed for speed, repetition and a single job, and a typical garment passes through several different machines between cut parts and a finished piece. Each machine makes a specific stitch, which is a pattern of thread loops that holds fabric together, and the choice of stitch decides the strength, stretch and appearance of a seam.
Six families cover most garment work. Lockstitch machines make the plain, firm stitch used on woven fabric and topstitching. Overlock machines trim and sew an edge at the same time and are the workhorse for knits. Coverstitch machines make the parallel rows seen on hems. Chainstitch machines make a looped stitch with a distinctive back. Bartack machines make short, dense stitching for reinforcement. Buttonhole and button attaching machines do those two jobs automatically.
Our guide to overlock, coverstitch and flatlock stitches explains the stitches in detail. This page focuses on the machines that make them.
Lockstitch Machines
The lockstitch machine is the classic industrial sewing machine. It uses two threads, an upper thread and a bobbin thread, that lock together in the fabric to make a firm, flat stitch that looks the same on both sides. It is the main machine for woven garments, for topstitching and for attaching pockets, labels and waistbands. Many versions exist, including single-needle machines and twin-needle machines that sew two parallel lines.
The lockstitch has little stretch, so it is not used for seams that need to stretch with the body, such as the side seams of a jersey tee. On jeans and woven casualwear, it is used widely. Our guide to jeans stitching shows where lockstitch and chainstitch are used on denim.
Overlock Machines
The overlock machine, also called a serger, is the workhorse of knit garment production. It uses several threads and loops them over the edge of the fabric. At the same time, a blade trims the edge. This creates a seam that is stretchy, neatly finished and quick to make. A three-thread overlock is lightweight and suited to edges and light fabrics. A four-thread or five-thread overlock adds strength and is used for side seams, shoulder seams and attaching sleeves.
On a hoodie, overlock machines join the body panels, attach the sleeves and make many of the seams. Because the stitch loops over the edge, it needs no separate seam finishing. The trade-off is that overlock seams are slightly bulkier than a flat seam and can be felt against the skin, which is why some garments use a flatlock instead for comfort.
The main industrial sewing machines compared
| Machine | What it does | Typical uses | Key point |
|---|---|---|---|
| Lockstitch | Firm two-thread stitch, same on both sides | Woven seams, topstitching, pockets | Little stretch |
| Overlock or serger | Sews and trims the edge with looped threads | Knit side seams, shoulders, sleeves | Stretchy and fast |
| Coverstitch | Parallel rows on top, looped threads below | Hems, necklines and cuffs on knits | Stretchy and neat |
| Flatlock | Flat seam with ladder look on one side | Sportswear and comfort seams | Low bulk |
| Chainstitch | Looped stitch with a chain on the back | Jeans seams, waistbands | Strong and stretchy |
| Bartack | Short, dense zigzag of stitches | Reinforcing pocket openings and belt loops | Strength at stress points |
| Buttonhole and button machines | Make a buttonhole or sew on a button | Shirts, jeans, jackets | Automatic and repeatable |
A general reference. Machine names and capabilities vary by manufacturer.
Coverstitch and Flatlock Machines
The coverstitch machine makes two or three parallel rows of stitching on the right side of the fabric, with a looped thread covering the raw edge on the underside. It is the standard hem on t shirts, sweatshirts and many knits, and it stretches with the fabric so the hem does not break when worn. It is also used to attach neck tape, bind necklines and finish cuffs.
A flatlock machine joins two pieces edge to edge so the seam lies flat. On one side the seam has a neat ladder pattern, and on the other it has loops. It is common in activewear and underwear because the flat seam avoids bulk and rubbing. Because it has less strength than an overlock, it is used where comfort matters more than holding power.
How each stitch tends to behave in a seam
1 dot = low, 5 dots = high
| Stretch | Strength | Flat and comfortable | Speed | |
|---|---|---|---|---|
| Lockstitch | ●●●●● | ●●●●● | ●●●●● | ●●●●● |
| Overlock | ●●●●● | ●●●●● | ●●●●● | ●●●●● |
| Coverstitch | ●●●●● | ●●●●● | ●●●●● | ●●●●● |
| Flatlock | ●●●●● | ●●●●● | ●●●●● | ●●●●● |
| Chainstitch | ●●●●● | ●●●●● | ●●●●● | ●●●●● |
Indicative ratings based on typical behaviour, not measured results.
Chainstitch, Bartack and Specialist Machines
A chainstitch machine uses a looped stitch that can be formed with one or two threads. It is strong and stretchy and is common in denim, where it gives the characteristic puckered look of a felled seam. Specialist versions include feed-off-the-arm machines, which sew a tube such as a leg inseam without opening it flat, and are widely used on jeans.
A bartack machine sews a short, tight pattern of overlapping zigzag stitches to reinforce stress points, such as the corners of pockets, the ends of belt loops and the base of a zip. Buttonhole machines cut and stitch a buttonhole in one operation, and button attaching machines sew a button to a set number of stitches, which makes them quick and consistent. Many factories also use snap, rivet and eyelet machines for hardware.
Which Machine Makes Which Seam on a Hoodie or Tee
Reading a garment by the industrial sewing machines it needs is a good way to understand its construction. A hoodie uses overlock machines for the body and sleeves, coverstitch machines for hems and cuffs, flatlock or overlock for the hood seams depending on the design, bartack machines for pocket openings and a coverstitch or lockstitch for attaching neck tape. A tee uses overlock for the shoulders and sides, coverstitch for the neck and hem and a coverstitch or lockstitch for the sleeve hems.
Machines used to make a hoodie and a tee
| Part of the garment | Typical machine | Why |
|---|---|---|
| Shoulder and side seams on a tee | Overlock | Stretchy, finished edge |
| Neck binding on a tee | Coverstitch | Stretchy and neat on a curve |
| Hem and sleeve hems | Coverstitch | Stretch with the fabric |
| Hoodie body and sleeve joins | Overlock | Strong, fast seams on heavy knit |
| Rib cuffs and hem band | Overlock or coverstitch | Joins rib to body with stretch |
| Pocket openings | Bartack | Reinforces the stress point |
| Hood drawcord channel | Lockstitch or coverstitch | Fixes the channel neatly |
A general guide. Construction varies by style and factory.
Machine families used across the seven examples above
7 example seams
- Overlock29%
- Coverstitch29%
- Bartack14%
- Lockstitch14%
- Mixed or choice of two14%
A count across the seven rows of the table: two overlock, two coverstitch, one bartack, one lockstitch and one mixed, rounded to whole per cent. A map of this page, not industry data.
Needles, Thread and Machine Settings Matter Too
The machine is only part of the story, and industrial sewing machines depend on setup. The needle type and size must match the fabric: a ballpoint needle for knits, to avoid cutting the yarn, and a sharp needle for woven fabric. The thread must match too, with the right fibre, thickness and colour. The stitch length, tension and presser foot pressure are set for each fabric and each operation, and a small error can cause puckering, skipped stitches or broken threads.
Maintenance and setup therefore matter as much as the industrial sewing machines themselves. A well-kept machine with correct settings makes a consistent seam, and a poorly kept one does not. When you visit a factory or look at photographs, watch for clean machines, organised needle stock and operators who check seams as they work. Our guide to common garment defects lists the faults, such as skipped stitches and puckering, that point to a machine or setup problem.
Setting up a machine for a new fabric
- 1Choose the needleBallpoint for knits, sharp for woven
- 2Choose the threadRight fibre, thickness and colour
- 3Set stitch lengthMatch to the fabric and the seam
- 4Set tensionBalance so seams lie flat without puckering
- 5Sew a test pieceCheck strength, stretch and look before running bulk
A simplified method. Factories add their own checks.
How Machines and Line Layout Work Together
Machines are arranged on the sewing floor according to the sequence of operations. In a bundle or unit system, each operator has a machine suited to one operation, so the line is a series of different machines in order. Modular teams may have a few machine types in a small cell. The mix and number of machines decide how many garments of a given style the factory can sew in a day. Our guide to garment production line types explains the layouts.
For a buyer, the point is that a factory's capability for a style depends on having the right industrial sewing machines in the right numbers. A factory with plenty of overlocks but few coverstitch machines may struggle with a style that needs a lot of hems. Ask which machines your style needs, whether the factory has them available and how many will be used.
Hand Work and Automation on the Sewing Floor
Not every operation uses a standard machine. Some factories use automated workstations for repeated tasks, such as pocket setting or buttonholing, where a template holds the fabric and a machine sews a programmed pattern. Others rely on skilled operators using standard machines and guides. Automation can improve consistency and speed on large runs of one style, but it needs setup time, so it suits long orders more than short ones. For small orders, skilled hand-guided work may be more practical. See our cut and sew clothing manufacturer guide for how factory type relates to order size.
Automated workstations vs hand-guided machines
Automated
- Automated: repeatable stitch patterns on long runs
- Automated: less dependence on operator skill for one task
- Automated: can raise output on a fixed operation
Hand-guided
- Hand-guided: flexible for small runs and varied styles
- Hand-guided: no template setup time
- Hand-guided: quality depends more on operator skill
A general comparison. Many factories use both, depending on the operation and order size.
Questions to Ask About a Factory's Machines
You can learn a lot from a few questions. A confident answer shows that the factory knows its equipment, and a vague one suggests that it may be improvising. Use the list below on a visit or a video call.
Machine and equipment checklist
- Which machines will make each seam on my style?
- Does the factory have the needed machines, and how many are available?
- Are the machines maintained, and how often are they serviced?
- Which needle and thread types will be used for my fabric?
- How are stitch settings checked for each new style?
- Is there a test piece or sample sewn before bulk starts?
- How is seam strength or stretch tested where it matters?
- Who is responsible if a machine fault causes defects?
A general list. Add anything specific to your product.
If a sample shows puckering, skipped stitches or weak seams, ask whether it is a pattern issue or a machine setup issue. Fixing it before bulk is far cheaper than finding it in a carton.
How Ruhrose Thinks About Machines and Stitches
Ruhrose develops hoodies, fleece, jersey, denim and woven casualwear with production in Bangladesh and UK buyer support. We name the stitch type for each seam in the specification, confirm that the factory has the right machines for your style and check the sample for seam quality before bulk. We do not publish prices or minimums here, because they depend on the style and quantity. The ISO publishes the standard that classifies stitch types, and the ASTM International publishes textile standards. To discuss a style, visit Ruhrose and send a reference garment.