Open a tech pack from a US factory and you will see numbers like 301, 504, and 607 where you expected plain words. For a new brand owner, those codes are confusing, and ignoring them is expensive. The stitch you pick changes seam strength, stretch, thread use, and which factory can sew your product. Let’s start with what each stitch means for your production decisions.
Knowing each stitch helps you decide how strong, stretchy, and clean each seam must be before you pay for a sample.
This guide covers nine types of stitches by class. You get uses, properties, thread use, and factory availability for each one.
Why Do Stitch Types Matter for Brand Owners?
The types of stitches you choose set seam strength, stretch, edge finish, thread use, and the machine your factory needs. A stitch is one repeating loop or lock of thread, and a seam is the line of stitches that joins two pieces of fabric. The ASTM D6193 standard sorts stitches into six numbered classes, and the same numbering appears in ISO 4915.
Writing those numbers into your tech pack gives the factory one clear spec to price. Fabric changes the answer too, because knits and wovens need different seams. The table shows the six classes and where each stitch in this guide fits.
ASTM D6193 Class | Name | Types in This Guide |
100 | Single-thread chain stitch | 101, 103 |
200 | Hand stitch | Not covered (hand work) |
300 | Lockstitch | 301, 304 |
400 | Multi-thread chain stitch | 401, 406 |
500 | Overedge and safety stitch | 504, 515, 516 |
600 | Covering chain stitch | 602, 607 |
9 Types of Stitches: The Complete List
These nine are among the most common stitches in apparel production, and each carries a number you can write into your tech pack. SPI (stitches per inch) is the number of stitches sewn in one inch of seam. Thread use below comes from Coats thread consumption ratios. A ratio of 2.5 means 2.5 inches of thread per 1 inch of seam at a reference density of 18 SPI.
1. Lockstitch (Type 301)
A lockstitch uses a needle thread and a bobbin thread that interlock inside the fabric.
Best for: Strong, clean seams on woven fabric. Properties: The stitch looks the same on both sides, resists unraveling, and has little stretch. Common use in fashion: Shirt plackets, trouser pockets, collars, and cuffs.
Lockstitch is the most common of all types of stitches in ready-made garments, so finding a factory that offers it is rarely a problem. It is also the lightest on thread, at a Coats ratio of 2.5.
2. Zigzag Lockstitch (Type 304)
A zigzag stitch is a lockstitch that moves side to side, which adds give and covers a wider area.
Best for: Seams and edges that need some stretch or extra security. Properties: Two-thread lockstitch security with a wider needle path. Common use in fashion: Intimate apparel, athletic wear, buttonholes, and bartacks.
American & Efird’s stitch guide prefers 304 for buttonholes, button sewing, and bartacks when stitch security is a must. A bartack is a dense block of short stitches that reinforces stress points such as pocket corners and belt loops. Coats does not list a thread ratio for it.
3. Single-Thread Chain Stitch (Type 101)
A single-thread chain stitch loops one needle thread back on itself, with no bobbin.
Best for: Temporary basting and quick, light work. Properties: Elastic and fast, but it can run back because each loop depends on the next. Common use in fashion: Basting and some button sewing.
One broken thread can undo a whole run, so avoid 101 on permanent seams unless the factory secures the ends. Confirm which chain stitch your factory means, because type 401 is far more secure.
4. Two-Thread Chain Stitch (Type 401)
A two-thread chain stitch pairs one needle thread with one looper thread, which forms a chain on the underside of the seam.
Best for: Long main seams on woven garments. Properties: No bobbin to refill, more seam stretch than a lockstitch, and a flexible, strong seam. Common use in fashion: Waistbands and long main seams on woven garments.
Coats notes that type 401 gives higher productivity and greater seam stretch than a lockstitch. It also uses more thread, at a ratio of 5.5 against 2.5.
5. Overlock Stitch (Type 504)
An overlock stitch wraps one needle thread and two looper threads around the raw edge. It seals the edge and joins the seam in one pass.
Best for: Knit seams and fray-prone raw edges. Properties: Coats rates 504 as having excellent extension, and it does not unravel easily. Common use in fashion: T-shirt side seams, trouser inseams, and finished edges.
Overlock machines, called sergers in North America, are standard apparel equipment, and many trim the edge as they sew. Thread use is heavy at a Coats ratio of 14.0, more than five times a lockstitch.
6. Safety Stitch (Types 515 and 516)
A safety stitch runs a chain stitch and an overlock together, so one pass joins the seam and finishes the edge.
Best for: High-stress seams on woven garments. Properties: In type 516, the 401 chain stitch bears the load while the 504 overlock covers the edge. Type 515 is the four-thread version, built from a 401 and a 503. Common use in fashion: Side seams, inseams, and armholes on woven garments.
Safety stitching is one of the types of stitches that needs a machine with both needle and looper sets, so confirm your factory owns one. Thread use adds up, with the 401 at 5.5 and the 504 at 14.0 running together.
7. Coverstitch (Types 406 and 602)
A coverstitch sews parallel needle rows on top and a looper thread underneath, which hems knit fabric without losing stretch.
Best for: Hems and elastic attachment on knits. Properties: Flat, comfortable, and highly stretchy, with two parallel rows on the face. Common use in fashion: T-shirt bottom hems, sleeve hems, and polo hems.
Coverstitch is one of the types of stitches that run on machines separate from sergers, so ask any knit factory to confirm it has one. Coats lists thread use at 18.0 for the three-thread type 406 and 25.0 for the four-thread type 602.
8. Flatlock Stitch (Type 607)
A flatlock stitch is a four-needle, six-thread coverstitch that joins fabric edges into a flat, durable, elastic seam.
Best for: Seams that touch skin, such as activewear and underwear. Properties: Flat, low-profile, and elastic. Common use in fashion: Athletic wear seams, base layers, and underwear construction.
A 2023 paper in Tekstilna industrija notes that flatlocks are not typical sewing machines, so ask early whether your factory owns one. Coats does not list a ratio, but type 607 uses six threads against four for type 602.
9. Blind Stitch (Type 103)
A blind stitch is a single-thread chain stitch sewn so that no stitch shows on the outside of the garment.
Best for: Invisible hems. Properties: One thread, low stitch density, and no visible stitch on the outside. American & Efird lists 3 to 5 SPI for it. Common use in fashion: Hems on trousers, skirts, and coats, plus belt loops.
Among the types of stitches here, blind stitching needs a dedicated machine, so confirm your factory has one before you design an invisible hem.
Those are the nine you will meet most often on a US tech pack. Whichever stitches you choose, vet the factory that will sew them. SCORE advises weighing quality and reliability alongside price when you pick a supplier.
Types of Stitches at a Glance: Comparison Table
This table compares all nine stitches by best use, key properties, thread-based cost impact, and what to confirm with a US factory. Cost impact is thread use per inch of seam from Coats ratios, and a higher number means more thread.
Type | Best For | Properties | Cost Impact (Thread Use) | USA Availability |
301 Lockstitch | Woven seams | Same both sides, little stretch | Lowest listed: 2.5 | Most common stitch in ready-made garments |
304 Zigzag | Buttonholes, bartacks, intimates | Lockstitch security, wider path | Not listed by Coats | Confirm bartack and buttonhole capacity |
101 Single-thread chain | Basting | Fast, can run back | Not listed by Coats; one thread | Common for basting; avoid on permanent seams |
401 Two-thread chain | Long woven seams | No bobbin, more stretch | 5.5 | Common on woven lines; ask about seam ends |
504 Overlock | Knit seams, raw edges | Stretches, resists fraying | 14.0 | Standard serger equipment |
515 / 516 Safety | High-stress woven seams | Chain stitch plus overlock | 5.5 (401) plus 14.0 (504), run together | Needs a safety-stitch machine |
406 / 602 Coverstitch | Knit hems, elastic | Parallel rows, very stretchy | 18.0 (406) and 25.0 (602) | Needs a coverstitch machine |
607 Flatlock | Activewear, underwear | Flat, elastic, durable | Not listed by Coats; six threads | Specialized machine; ask early |
103 Blind stitch | Invisible hems | One thread, no visible stitch | Not listed by Coats; one thread at 3 to 5 SPI | Needs a blind-stitch machine |
Here is what thread use means on a real seam. At Coats’ 18 SPI reference density, a 36-inch side seam uses about 90 inches of thread as a 301 lockstitch. The same seam uses 198 inches as a 401 chain stitch and 504 inches as a 504 overlock.
How Do You Choose the Right Stitch for Your Brand?
Choose between the types of stitches by matching four things. Those are fabric stretch, seam stress, what the customer sees and feels, and the machines your factory owns. Work through these five questions before you finalize your tech pack.
- Does your fabric stretch? Of the types of stitches here, stretch knits need an overlock (504), coverstitch (406 or 602), or flatlock (607). Woven fabric usually takes a lockstitch (301) or chain stitch (401).
- How much stress will the seam take? Add a safety stitch (516) or bartacks at stress points such as pockets and belt loops.
- Will the customer see or feel the seam? Among these types of stitches, choose a flatlock for skin contact and a blind stitch for invisible hems. For visible lines, read our guide to understitching, topstitching, and edgestitching.
- What SPI does your fabric need? Higher SPI makes a tighter seam but costs more thread and time.
- Which machines does your factory own for these types of stitches? Ask for a machine list, then confirm the stitch on a paid sample before you commit to production.
These questions narrow your options to two or three candidates for each seam.
Kohl’s published apparel construction requirements (2026 edition) show typical SPI targets from one major US retailer. Your own fabric and factory may differ, so treat these as starting points.
Fabric or Use | Typical SPI (Kohl’s, 2026) |
Denim, twill, corduroy, stretch waistbands | 8 to 10 |
General woven apparel | 10 to 12 |
Men’s woven shirts | 12 to 14 |
General knit sewing | 10 to 12 |
Knits with more than 7% spandex | 14 to 16 |
If you are new to production, SBA’s manufacturing hub lists free resources for small businesses working with US manufacturers.
Also Read: How to Find a Clothing Manufacturer in the USA →
Finding Manufacturers by Stitch Type on Maker’s Row
You can find manufacturers who sew specific types of stitches by listing your stitch numbers in a project brief on Maker’s Row. Maker’s Row is a marketplace connecting apparel brand owners with verified US manufacturers.
Finding a factory that sews the types of stitches you need does not have to mean months of cold emails. Post your stitching project for free and verified US manufacturers bid directly. Review bids, check profiles, connect when ready. List the types of stitches you need in your project brief, and factories with the right machines can respond to exactly what you need.
On Maker’s Row, brand owners post unlimited manufacturing projects for free and receive bids from verified US factories at no upfront cost. To connect directly, subscription plans give full access.
FAQs About Stitch Types
Garment manufacturing groups stitches into six ASTM D6193 classes: single-thread chain (100), hand (200), lockstitch (300), multi-thread chain (400), overedge (500), and covering chain (600). Each class holds numbered types of stitches, such as 301 for a straight lockstitch and 504 for a three-thread overlock.
The lockstitch (type 301) is the most common stitch in garment manufacturing, especially on woven fabric. It also uses the least thread of all the types of stitches Coats lists, at a ratio of 2.5.
A lockstitch interlocks a needle thread with a bobbin thread, while a chain stitch (type 401) uses a looper thread and needs no bobbin. Chain stitches stretch more but can unravel if the ends are not secured. Both are common types of stitches, but they suit different seams.
An overlock wraps threads over the raw edge to seal and join it. A coverstitch sews parallel rows on the face to hem or attach elastic without wrapping the edge. Both are common types of stitches on knits. Overlock (type 504) is the standard seam, and coverstitch (types 406 and 602) is the standard hem.
The best stitch for stretch fabric is one that stretches with the fabric. Among these types of stitches, use an overlock (504) for seams, a coverstitch (406 or 602) for hems, or a flatlock (607) for flat seams.
Across the common types of stitches, most garments use 8 to 14 stitches per inch, depending on fabric and use. Kohl’s 2026 requirements list 10 to 12 SPI for general woven apparel and general knits. They list 12 to 14 for men’s woven shirts and 8 to 10 for denim and twill.
Not every US factory offers every one of the types of stitches, because each stitch needs specific machines. The U.S. Bureau of Labor Statistics counted 6,199 private apparel manufacturing establishments in the first quarter of 2026 (preliminary) and 25,280 sewing machine operators in 2025. With that many shops, equipment varies widely, so ask for a machine list and request a sample of the exact stitch you need.
Now You Know the Types. Here Is Your Next Step
Your apparel brand is one manufacturer away from becoming real. The factories are on Maker’s Row, ready to bid.
