A stitch is a unit formed by one or more threads passing into or through the fabric. The international standard ISO 4915 classifies stitch types into six classes, numbered 100 to 600. Garment specifications use these numbers, so it helps to know the common ones.
The six stitch classes#
| Class | Name | How it is formed |
|---|---|---|
| 100 | Single thread chainstitch | One thread interloops with itself |
| 200 | Hand stitches | Originally made by hand; one thread passes through the fabric |
| 300 | Lockstitch | Two or more thread groups interlace |
| 400 | Multi-thread chainstitch | Needle threads interloop with looper threads |
| 500 | Overedge (overlock) chainstitch | Threads interloop around the fabric edge |
| 600 | Covering chainstitch | Needle threads with top and bottom cover threads over the seam |
Common stitch types#
301 Lockstitch#
- Formed by: a needle thread and a bobbin thread interlacing in the middle of the fabric.
- Looks: the same on both sides.
- Used for: woven garments, topstitching, pocket attaching, labels, collars, plackets.
- Strengths: secure, neat, does not unravel easily.
- Weaknesses: limited stretch; bobbin must be changed often; can cause puckering on fine fabrics.
304 Zigzag lockstitch#
A lockstitch that moves sideways, giving more stretch. Used for elastic attaching, lingerie and decorative seams.
401 Two-thread chainstitch#
- Formed by: a needle thread and a looper thread interloop underneath.
- Used for: long seams on jeans and trousers, waistbands (multi-needle), inseams.
- Strengths: more stretch than lockstitch, large thread packages (no bobbin), fast.
- Weaknesses: can unravel if the end is not secured and a stitch is broken.
406 Coverstitch (two needles, bottom cover)#
- Used for: hems and binding on knits, attaching elastic.
- Strengths: stretch, flat and neat on the face, covers raw edge on the back.
503, 504 Overlock (2 and 3 thread)#
- Used for: edge neatening (serging) on woven parts, seams on light knits.
- Strengths: trims and covers the edge in one step; stretches well.
512, 514 Four-thread overlock (mock safety and full four-thread)#
- Used for: main seams on knit garments: side seams, shoulders, sleeves.
- Strengths: strong, stretchy, neat.
516 Safety stitch (401 + 504)#
A two-needle chainstitch and an overlock sewn together. Used for strong seams on wovens such as jeans and workwear.
602, 605 Covering chainstitch (top and bottom cover)#
- Used for: flat seams and decorative binding on knits, underwear and sportswear.
607 Flatlock#
- Used for: flat butted seams on sportswear and underwear, where a bulky seam would rub.
Choosing a stitch#
| Need | Suitable stitch types |
|---|---|
| Stretch seam on knit | 504, 514, 406, 607 |
| Secure topstitch on woven | 301 |
| Long, strong seam on denim | 401, 516 |
| Neat knit hem | 406, 602 |
| Flat, comfortable seam | 607, 605 |
| Edge neatening on woven | 503, 504 |
The fabric's stretch, the seam's stress in wear, appearance and production speed all matter. A stitch that stretches less than the fabric will crack when the garment is stretched.
Thread consumption by stitch type#
Different stitches use very different amounts of thread per cm of seam: a lockstitch may use about 2.5 cm of thread per cm of seam, a four-thread overlock well over 15. Measure the ratio on your fabric and stitch density. See thread consumption.
Related#
Related guides#
- Sewing needle selection: the needle for each machine and stitch.
- Seam strength: testing the strength of the seams these stitches make.