Flatlock seam (4-thread)
Also known as: 4-thread flatlock, Flat seam 4-thread
Butt seam with four threads that joins two fabric edges edge-to-edge and covers them flat — low chafing on skin, classic for sports and functional underwear.
Description
The 4-thread flatlock seam is the technical evolution of the classic flatlock. It combines two needle threads with two looper threads to form a virtually flat joining seam with no seam allowance inside — the two fabric edges butt against each other and are fully covered by a dense chain-stitch overlay.
Benefits are very high stretch (up to 200 %), extreme flatness (no seam ridge against the skin), good tensile strength and a clean, athletic inside appearance. Thread consumption is relatively high at 12-16 m per seam metre. The 4-thread flatlock is used on close-fitting sports baselayers, cycling wear, compression and yoga apparel and functional underwear, where chafing and seam ridges must be avoided at all costs.
- Thread count: 2 needle + 2 looper = 4 threads
- Stretch: up to about 200 %
- Thread use: 12-16 m per seam metre
- Use: baselayers, cycling, yoga, compression wear
Properties
| Thread count | 2 needle + 2 looper |
|---|---|
| Stretch | Up to about 200 % |
| Standard | ISO 4915 class 606 |
| Application | Sports baselayers, cycling, yoga, compression wear |
Related product categories
Sources & references
2- ISO 4915: Textiles — Stitch types ISO — International Organization for Standardization https://www.iso.org/standard/10932.html
- Wikipedia: Flatlock seam Wikipedia — Freie Enzyklopädie https://en.wikipedia.org/wiki/Overlock
