The machine is equipped with a link feeding mechanism which is highly evaluated for its straightness consistency and durability. Also it enables, the machine to sew well-tensed beautifully finished seams, regardless of the type of heavy-weight materials. The maximum stitch length is as long as 8 mm (with the L-type machine for heavy-weight materials with long stitch length), thereby making the machine widely applicable to the sewing of heavy-weight materials, such as bags, requiring a long stitch length Changing the bobbin is troublesome, especially when using a thick thread. This machine, however, is equipped with a double-capacity hook, thereby reducing the frequency of changing the bobbin. By this feature, greater efficiency is assured.