Singer 337 Sewing Machine User Manual


 
15
_ _:_ BOBBIN THREAD TENSION __ _._L
STRAIGHT STITCHING
Bobbin thread tension too tight--
correct by turning screw counterclock-
wise.
Bobbin thread tension too loose--
correct by turning screw clockwise.
A perfectly locked straight stitch results with upper and lower tensions balanced
so that needle and bobbin threads are drawn equally into fabric.