Sandvik Coromant Threading - Manual (Page 29)

29
(

(
)
(
)
60° 7.6° 5°
55° 7.1° 4.7°
30° 4° 2.6°
29° 3.8° 2.5°
10° / 3° 2.7° / 0.8° 1.8° / 0.5°
2. Applications – Thread turning
Relationship between fl ank clearance, radial clearance and
thread profi le angle
The smaller the thread profi le and radial clearance angles, the
smaller the fl ank clearance angle (see table below for fl ank clear-
ance values when the correct shim, equal to the helix angle, is
used).
Please note that as the profi le angle becomes smaller, it is more
important to choose the correct shim.
Threads with small profi le angles
ACME, Stub ACME, trapezoidal and rounded threads fall into this
category and put extra pressure on the cutting edge. To minimize
this pressure, choose the correct shim to tilt the insert.
Thread
Profi le Angle Internal 15° External 10°
Flank clearance Flank clearance
Metric, UN
Whitworth
Trapezoidal
ACME
Buttress
Radial
clearance (
)
Flank
clearance