Single needle lockstitch zig-zag machine for a wide range of materials from light to medium heavy fabrics. Embroidery can also be accomplished on these varieties. Independently adjustable and variable forward and reverse feed system facilitates ease of backstitching. Stitch width can be adjusted freely by using a knee operated bight control. Stitch width can also be fixed. Hook advancing and retarding mechanism which allows zig-zag sewing at wide bights (max. bight 8 mm). Easily convertible to embroidery or zig-zag or straight stitching. Provided with a needle position control device which makes it possible to produce buttonholes.