Sandvik Coromant Threading User Manual
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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. Technical reference
Flank clearance depending on profi le
Multi-start threads
If the thread has multi-starts, calculate the helix angle with this
formula.
Tread profi le
Angle (
)
Internal 15° (
)
External 10° (
)
Metric. UN
Whitworth
Trapezoidal
ACME
Buttress
Angle of insert inclination
Radial clearance
Flank clearance