Stitches and Seams

Class 100

Each loop is interconnected with the following loops of the same thread. The opposite sides of the seam look different. The unpicking/unraveling of this stitch type is very easily done by running back from the end of the stitch line to the first stitch. This stitch class is often used for temporary stitching e.g. basting.

Stitch class 100

Class 200

Needle and thread are both passed completely from one side of the material to the other. The thread is held through the material. This stitch type is originally made only by hand, but there are also machines available that can form this stitch type. This stitch type is used mostly for making edges.

Stitch class 200 (Type 209)

Stitch class 200 (Type 209)

Class 300

It requires at least two thread systems for a stitch formation. The needle thread wound on the spool is mounted on top of the machine. The bobbin thread is wound on a small bobbin, which is encapsulated inside a bobbin case. The needle takes the needle thread through the sewing material which is taken by a hook system rotating around the bobbin case. The hook takes the loop of needle thread around the bobbin case. After looping the needle thread around the bobbin case, the thread take-up lever pulls the needle thread back and the bobbin thread upwards to sewing material. In such a fashion, a stitch is formed. Usually, the interlacing point of two thread systems is formed between the sewing material which shows a balance of thread tensions between needle and bobbin threads. But after adjustments of tensions of sewing threads, the interlacing point can be shifted to either side (top or bottom) of the sewing material. Lockstitch has a similar appearance on both sides of the stitch.

Stitch class 300 (Lockstitch)

Stitch class 300 (Lockstitch) [Groz-Beckert]

Class 400

The stitch is formed by two different thread systems. The loops of the needle thread are drawn through the material and are interloped on the lower side of the material with another thread system supplied by the looper. The top and bottom sides have different appearances. The stitch is extensible and also be unpicked easily. This seam type is used in side seams, inseams, seat seams.

Stitch class 400 (Type 401)

Class 500

The stitch is formed from one or more needle and looper thread systems. The loops of needle threads are taken all the way through the material and are interlaced with themselves or with other threads. At least one thread system is passed by the edge of the stitch. This stitch type is used to cover the edges ad protect the material yarns from fraying. The machines of class 500 are usually coupled with a blade system which cut the extra material and prepare the edge for stitching. 

Stitch Class 500 [Groz-Beckert]

Class 600

The stitch type is usually formed with three thread systems. The cover thread lies on the top surface and is held in place by needle threads. At least two needles are required from this stitch type. The needle threads interlace with looper thread on the back of the seam. This stitch type is used for flat surfaced extensible seams on extensible fabrics.

Stitch class 600 (Type 602)