There are many classification methods for sewing machines, and the more common one is to distinguish them by stitches and uses. The stitches of the sewing machine can be classified into two types: lock stitch and chain stitch. The lock stitch is the most common. It consists of two sutures, which are interwoven with each other like a twisted rope. The interlacing point is in the middle of the sewing material. Viewed from the cross section of the stitches, the two stitches are like two locks locked to each other, so they are called lock stitches. This stitch is used for sewing materials such as cotton, wool fabric or leather with low shrinkage. The front and back sides have the same shape, like a dotted line. The stitches are densely distributed, and the sewing fastness generally exceeds that of manual sewing.
Chain stitches are formed by self-connection or interconnection of suture loops. Commonly used are single-thread chain, double-thread chain and three-thread overlock stitches. This kind of stitch is characterized by its elasticity and can stretch with the sewing material without breaking the stitch. It is suitable for clothes made of thread elastic fabrics or products and garment blanks that are easy to be sewn.
In addition, sewing machines can be divided into household, industrial, and service industries according to their uses. According to the driving mode, they can also be divided into hand-operated sewing machines, pedal sewing machines, and electric sewing machines.
