Page 34 - Iscar_Article_Brochure

"We now use thread milling here for threads from
M27 to M100," says Bender. "The MILLTHREAD
thread milling system excels in particular for
large size threaded bores for screw insertion, for
example on the gas turbine surfaces where the
halves of the casing are subsequently joined, as
well as on the front surfaces or at the flanges.
"Compared to conventional whirling, this special
technology makes it possible to cut machining
times on average by a factor of 3 to 4. Compared
to thread tapping, on the other hand, the
advantage lies in the greater process reliability
rather than in increased productivity. In light of
the high component costs, this is another very
persuasive argument in favour of the system,"
stresses the industry specialist. It soon became
clear that the tool system was exceptionally well
suited to the Siemens applications. Nevertheless,
some difficulties occurred with certain
combinations of thread types and milling tool
diameters. More specifically, with the thread sizes
M56x5.5 and M27x3 – "two sizes which are right
at the limit when it comes to profile distortions,"
as Bender describes it. After the corresponding
trials had been completed in the ISCAR Test
Centre in Ettlingen Germany, it proved possible to
manufacture the thread types in flawless quality
and release these for the customer. According
to Zapke, the geometry of the indexable cutting
inserts was also beneficial. "In itself, thread milling
was nothing new for us, however, the shape of the
inserts was new.

These inserts are rotated and permit a soft cut.
All of this have enabled ISCAR to manufacture
these components, which have a critical influence
on improved cycle times. Although there are other
suppliers of thread milling tools, ISCAR offers a
full product portfolio.

Whenever we change a technology used in the
company, we always make sure that the system can
be used not just at one specific workplace but also
in other areas.

We produce threads from M6 through to M100x6,
and with ISCAR's thread mills we can cover our

34