Thread Tension; Adjusting The Thread Tension - Brother T-8421B Instructions Manual

8. THREAD TENSION

8. THREAD TENSION

8-1. Adjusting the thread tension

Good even stitches
<Latch type>
Becomes weaker
<Bobbin case type>
2923M
Becomes stronger
Becomes weaker
35
Upper thread
Lower thread
0572M
Upper thread tension too weak or
lower thread tension too strong
0573M
Upper thread tension too strong
or lower thread tension too weak
0574M
2922M
Becomes stronger
Becomes stronger
Becomes weaker
Becomes weaker
Becomes stronger
2924M
T-8421B, 8422B, 8452B, 8722B, 8752B
Increase the upper thread tension.
Decrease the lower thread tension.
Decrease the upper thread tension.
Increase the lower thread tension.
<Lower thread tension>
CAUTION
Turn off the power switch before adjusting the
lower thread tension.
The machine may operate if the treadle is
depressed by mistake, which could result in injury.
Turn the adjusting screw (1) to adjust.
<Upper thread tension>
After the lower thread tension has been adjusted, adjust the
upper thread tension so that a good, even stitch is obtained.
1. Lower the presser foot.
2. Adjust by turning the tension nut (2).