One of the most significant advantages of heavy-duty sewing machines is their strong motor. This powerful motor enables them to sew at higher speeds and through tougher materials compared to normal machines. Many models can reach speeds of up to 1,100 stitches per minute, making them ideal for large projects that require efficient stitching. Additionally, heavy-duty machines often include features like adjustable stitch length and width, which provide users with more control over their sewing for various applications.

The lock stitch is formed when the needle penetrates the fabric, carrying the upper thread down into the fabric. The bobbin, located beneath the needle plate, feeds the lower thread and forms a lock with the upper thread, resulting in a firm stitch that is visually appealing on both the front and back of the fabric.

Overlock chain stitch, commonly referred to as a flatlock stitch, is a technique primarily used for finishing seams and edges in fabric. It is created using an overlock sewing machine that typically operates with a combination of loopers and needles. Unlike standard straight stitches, which simply interlock threads, the overlock chain stitch utilizes multiple threads to create a series of interlocking loops. This results in a stitch that is both flexible and durable, making it ideal for knit and stretch fabrics.