9 TWO – THREAD SERGING
Two – thread serging provides a decorative, but functional seam, known as the flatlock seam. On garments
ranging from lingerie to fake – fur coats it produces flat, non – bulk seam. Use it to seam fake – fur fabrics,
and you will find that the stitches “disappear” in the nap. When seaming active wear the decorative
appearance or flatlock can be enhanced with the use of metallic or variegated thread.
Besides flatlock seaming, two – thread serging provides an economical, yet sturdy means of overedging all
fabrics. When combined with specialty threads, two – thread stitching makes decorative edges for ruffles,
hemlines, borders and accessories.
Two – thread sewing is accomplished through the elimination of two threads (upper looper, green color –
coded path and either needle thread), and slight machine adjustments.
The stitch pattern for two – thread sewing has a slightly different appearance from that of three – thread
sewing. If tension is properly set, the needle thread forms a flat overedge loops on the underneath side of the
fabric, while the lower looper thread creates similar stitches on the top side of the fabric. Both threads lock
together at the cut edge as well as at the needle stitching line. (See Figure 60).
9 – 1 To convert from three – thread to two – thread sewing
1. Open the front cover and rotate the handwheel
to bring the upper looper to its lowest position.
2. Cut upper looper thread just behind the eye of
the looper, and without unthreading all the
thread guides, bring the loose thread up and
over its own tension disc (green). This keeps it
out of the way, and eliminates the need for
complete rethreading later.
3. Push on the subsidiary looper screw (brass)
with your finger or small screwdriver, and
rotate it to the left until the tip of the subsidiary
looper fits securely in the eye of the upper
looper, thus disengaging the looper.
4. Move the thread guide switch from the blue “3”
to the red “2”. Be careful not to move the
switch lower than necessary.
5. Adjust tension. (See page 35).
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