Owner's manual
116
= arctan
sin
tan()
2
= arctan
number of startsP
d
2
= arctan
P
d
2
60° 8.5° 6°
55° 7.5° 5°
30° 4° 2.5°
29° 4° 2.5°
10° / 3° 2° / 0.5° 2.5° / 0.5°
5
. T
ec
hni
ca
l r
efe
r
e
n
ce
Flank clearance depending on pro le
Multi-start threads
If the thread has multi-starts, calculate the helix angle with this
formula.
Tread pro le
Angle () Internal 15° () External 10° ()
Metric. UN
Whitworth
Trapezoidal
ACME
Buttress
Angle of insert inclination
Radial clearance
Flank clearance