SINGER W815 - Manual (Page 10)

10. REGULATING THE THREAD TENSION
For ordinary stitching the tension of the upper
and lower threads should be equal so as to lock
both threads in the center of the material (Fig.
13). If one tension is stronger than the other,
imperfect stitching will result. Fine materials
require a light tension, while heavy materials
require more tension to obtain -a perfect stitch.
TO INCREASE the tension, turn the thread
tension dial (Fig. 12) clockwise.
TO LESSEN the tension, turn the thread tension
dial in the opposite direction. (When regulat­
ing the tension always have the presser foot
down).
As all machines are correctly adjusted before leaving the factory and
readjusted before the dealer delivers them to you, the lower tension
seldom requires to be altered, but, if this becomes necessary, tighten
the screw holding the tension spring on the outside of the bobbin case
for more tension, or loosen the screw slightly for lesser tension (Fig. 14).
Correct Stitch
Fig 12
Needle Thread Tension too strong
Needle Thread Tension too weak
Fig 13