Technical Information
General Machining Guidelines
Modifi ed fl ank
modifi ed fl ank
Alternating fl ank
modifi ed fl ank
alternating fl ank
Reversed modifi ed fl ank
modifi ed fl ank
15º–29º 30'
15º–29º 30'
angle of
infeed
angle of
infeed
angle of
infeed
Advantage — Advantage — Advantage — Advantage —
• Cutting on both sides of the thread
form places all of the cutting edge
in the cut and protects edge from
chipping.
• Even wear on the insert. • Tool cuts both sides of thread form,
so it is protected from chipping
similar to 0° infeed. Channel-type
chip develops, but uneven chip
thickness helps remove the chip
similar to fl ank infeed.
• This is the preferred method,
especially when used with a chip
control insert.
• Combined radial and/or alternating
fl ank infeed.
• Results in good tool life, with wear
evenly distributed over both fl anks. • Increased tool life because both
edges are used equally. • Tool cuts both sides of thread form,
so it is protected from chipping
similar to 0° infeed. Channel-type
chip develops, but uneven chip
thickness helps remove the chip
similar to fl ank infeed.
• This is the preferred method,
especially when used with a chip
control insert.
• Combined radial and/or alternating
fl ank infeed.
• Results in good tool life, with wear
evenly distributed over both fl anks.
• As chip fl ow is the reversed feed
direction, it is an excellent choice
for internal threading.
Disadvantage — Disadvantage — Disadvantage — Disadvantage —
• Tool develops a channel chip that
may be diffi cult to handle.
• Tip chipping occurs when cutting
high-tensile materials.
• Bur condition is increased.
• Entire cutting edge is engaged at
fi nish of thread, causing increased
tendency to chatter. • Similar disadvantages as with 0°
infeed, although reduced somewhat
in magnitude as cutting forces are
better equalised and chip fl ow is
much less of a problem. • Diffi cult to cut on conventional
machinery. • Programming needs to be done
line by line.
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NOTE: Some machine tools may
require special programming
techniques to achieve this
method of infeed.
F85
Radial