twinneedle

A twinneedle, also known as a double needle, is a sewing machine accessory that features two needles mounted on a single needle bar. It enables the machine to stitch two parallel top lines simultaneously while the bobbin thread forms a single bottom stitch, creating a characteristic two-row topstitch with an interlocking underside.

Two separate top threads, typically from two spools, feed through the machine and into the two needles. The fabric is guided as usual, and the bobbin thread forms a zigzag or interlocking stitch on the underside between the two top stitches. The result is a finished edge or decorative detail with a professional, café-stitched appearance.

Compatibility and setup vary by machine. Most domestic machines require two adjacent needle positions and a compatible needle plate to accommodate the twin needles. Needle spacing is measured in millimeters and varies by model, commonly ranging from about 2.5 mm to 6 mm. When using a twinneedle, you thread both top threads as you would a single needle, and adjust tension as recommended by the machine’s manual. The bottom thread remains the bobbin thread. Some machines may require a different foot or a spacer; always consult your manual for specifics.

Common uses include hemming knit fabrics to preserve stretch, decorative topstitching on wovens, and creating a professional-looking finish on lightweight to medium-weight fabrics. Twinneedles are not suited for very thick materials, and tension adjustments are often needed to achieve even stitching.