threadtension

Thread tension refers to the amount of tightness applied to the thread during sewing. Proper thread tension is crucial for creating strong, even stitches. In sewing machines, tension is typically controlled by a tensioning mechanism, usually involving discs that press against the thread. The upper thread tension controls the tightness of the stitch as it enters the fabric, while the bobbin or lower thread tension controls the tightness of the stitch from underneath.

When thread tension is too loose, the stitches will appear loopy and slack on one side of the fabric, often the top. This can lead to skipped stitches or a weak seam. Conversely, if the tension is too tight, the thread can break, or the fabric may pucker or gather excessively. The ideal tension allows the upper and lower threads to interlock securely within the fabric layers, creating a balanced stitch that lies flat without distorting the material.

Adjusting thread tension is a common troubleshooting step in sewing. The correct tension setting often depends on the type of fabric, thread weight, and needle size being used. A general rule of thumb is to test the stitch on a scrap of the same fabric before beginning the actual project. This allows for fine-tuning of the tension dials until a consistent and balanced stitch is achieved on both sides of the fabric.