Thread Tension; Lower Thread Tension; Upper Thread Tension - Brother BAS-311H Basic Operation Manual

4. PREPARATION BEFORE SEWING

4-5. Thread tension

[Thread tension reference]
Specifications
Upper thread
Lower thread
Upper thread tension (N)
Lower thread tension (N)
Pre-tension (N)
Needle
Normal sewing speed

4-5-1. Lower thread tension

Weaker

4-5-2. Upper thread tension

26
Medium-weight materials
(-03[])
#50 or similar
#50 or similar
0.8 − 1.2
0.1 − 0.3
DP x 5 #16
2,000 sti/min
Stronger
Stronger
Weaker
Stronger
Weaker
Heavy-weight materials
(-05[])
#20 or similar
#20 or similar
1.4 − 1.8
0.2 − 0.3
0.1 − 0.6
DP x 17 #19
2,000 sti/min
Adjust the thread tension to the weakest possible tension by
turning the thread tension nut (1) until the bobbin case will
not drop by its own weight while the thread end coming out
of the bobbin case is held.
2536Q
1. Turn the tension nut (1) (main tension) to adjust the
tension as appropriate for the material being sewn.
2. Use the tension nut (2) (sub tension) to adjust the upper
thread trailing length to about 40 mm.
3067B
BAS-311H
Seatbelt (-07[])
#4 or similar
#4 or similar
1.2 − 2.0
1.0 − 1.5
0.3 − 0.6
DP x 17 #25
1,300 sti/min