flatlock
{{Unreliable sources|date=May 2025}}
Flatlock is a sewing machine stitch that butts two edges of fabric with no overlap.{{cite web |last1=Fasanella |first1=Kathleen |title=Flatlocking compared to cover stitching and overlocking |url=https://fashion-incubator.com/flatlocking-compared-to-cover-stitching-and-overlocking/ |website=Fashion-Incubator |language=en |date=18 February 2009 | access-date=25 May 2025}} The flatlock stitch is used on swimwear, active wear, and infant clothing.{{cite web |last1=Kiron |first1=Mazharul Islam |title=Flat Lock Sewing Machine: Parts, Specifications and Working Mechanism |url=https://textilelearner.net/flat-lock-sewing-machine-parts/ |website=Textile Learner |access-date=25 May 2025 |date=12 February 2012}}
Description
It is commonly used in sports wear as there are less fabric to chafe. A similar stitch can be achieved on overlock machines, but the result is thicker as the cloth slightly overlaps. However, some industrial overlock machines can do flatlock stitches.{{cite web |last1=Adscultin|title=Overlock vs. Interlock sewing machine - Balaji Sewing Machine Pvt. Ltd |url=https://balajisewing.com/blog/overlock-vs-interlock-sewing-machine/ |website=balajisewing.com |publisher=Balaji Sewing Machine pvt ltd |date=29 February 2024}} Yamato Sewing Machine Mfg. advertises their interlock sewing machines as "Flatlock/Coverstitch" machines.{{cite web |title=Interlock Sewing Machines (Flatlock Machines) {{!}} Products |url=https://www.yamato-sewing.com/en/product/interlock_flatlock/ |website=Yamato Sewing Machine Mfg. Co., Ltd. |publisher=Yamato Sewing Machine Mfg. Co., Ltd. |access-date=25 May 2025 |language=en}}.
While home overlock machines can produce a mock flatlock stitch that is similar to the flatlock of a commercial flatlock machine, it lacks strength because it only contains 3 threads instead of the 6 threads in a true flatlock stitch.{{cite web |last1=Lombardi |first1=Alex |title=Q&A: Real vs. Mock Flatlock |url=https://www.threadsmagazine.com/2019/06/26/qa-real-vs-mock-flatlock |website=Threads |publisher=Active Interest Media |access-date=25 May 2025 |date=26 June 2019}}