Singer 457 - Page 21

Adjusting Bobbin-Thread Tension
Bobbin-thread tension is controlled
by a screw located on the bobbin
case . You will seldom need to adjust
bobbin-thread tension since it is
usually possible to obtain the cor-
rect balance by
adjusting the
nee-
dle-thread tension alone .
On
those rare occasions when it be-
comes necessary to adjust
the
bob-
bin-thread tension, use the small
screwdriver that is among your ac-
cessories
.
A very- slight turn on the
screw nearest
the
thread
slot on the
bobbin case
will
produce a noticeable
change in bobbin-thread tension .
" To increase tension, turn screw
clockwise .
" To decrease tension, turn screw
counterclockwise .
Balanced Tension