SINGER 321D-241M-24 INDUSTRIAL SERGER - Manual (Page 16)

Thread Tension
Adjustment
Figure 16
Figure 17
13 Ultra High Speed Overedge and Safety Stitch Machine | Instruction Manual and Parts List
3.8
Important
The thread tension
should be adjusted
according to the
type and thickness
of the cloth,
sewing thread,
sewing width,
stitch length and
others. Therefore
the pressure of the
tension nuts or
thread guides
should be individu-
ally adjusted for
each case.
The following adjustments are related to Figure 16 &17.
Tension Nut 1: controls the needle thread or the left thread in
case of two needles.
Tension Nut 2: controls the thread in the right needle.
Tension Nut 3: controls the thread in the lower looper.
Tension Nut 4: controls the thread in the lower looper.
Tension Nut 5: controls the thread of the safety stitch.
To loosen
1
2
3
To tighten
3 3
4 4 4
4
5
2 2 1
3 3
2 1 2 1