Brother NS-40 Operation Manual page 60

Buttonholes with a maximum length of 30 mm (1-3/16 inches) (diameter + thickness of the button) can be sewn.
Buttonholes are sewn as shown below.
a Reinforcement stitching
CAUTION
● Before replacing the presser foot, be sure to turn off the sewing machine, otherwise injuries may occur if a
button is accidentally pressed and the machine starts sewing.
The names of parts of buttonhole foot "A", which is used for sewing buttonholes, are indicated below.
a
b
e
c
d
A
a
a
a Button guide plate
b Presser foot scale
c Pin
d Marks on buttonhole foot
e 5 mm (3/16 inch)
a
3
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