Overlock & serger machines

Overlock and serger machines are specialised textile machines that simultaneously perform three operations: they cut the fabric edge with a knife, cover the cut with a multi-thread chain stitch (2, 3 or 4 threads) and advance the fabric with a differential feed system. The result is a trimmed, fray-sealed and stitched edge in a single pass — operations that with a conventional sewing machine would require three separate stages.

The distinguishing feature of the overlock is the elasticity of the stitch: the chain stitch stretches and recovers with the fabric, making it the machine of choice for jersey, knitwear, sportswear and any garment requiring an elastic seam. The differential feed allows the gather effect to be controlled or fabric waves to be avoided on stretch materials. In the maker and dressmaking context, the overlock is often paired with the main sewing machine for quality inner finishes.