Page 27 - Iscar Article 2_2017
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guidelines, etc.) are cut, which improves tool life carrying indexable inserts, the rake angles are
and makes machining much more accurate and defined by the topology of the insert rake face and
predictable. the insert positioning in the cutter. The
topology is a key factor in varying rake angles.
Cutting tools have a major role to play in
this area. Total power requirements can be In the early nineties, ISCAR introduced the
moderated by the use of advanced new tools HELIMILL – a family of milling tools carrying
and innovative milling tools offer promising indexable inserts with a helical cutting edge.
opportunities in particular.
Leading-edge cutting geometry
When milling, power consumption depends on
several parameters, including workpiece material,
depth and width of cut, cutting speeds and feeds.
A combination of these influences defines the
material’s resistance to machining, and the total HELIMILL with
helical-shaped cutting edge
cutting force generated during the process. There
is another important factor closely connected The highly effective edge was generated by the
with these forces – the geometry of the tool being intersection of the shaped insert top (rake) face
used; more specifically, the tool rake angles in and the helical insert side (relief) surface. The
both normal and axial directions. design of the HELIMILL tools formed a constant
positive normal rake and a positive axial rake along
The standard rake significantly affects the all cutting lengths. This feature immediately caused
tangential cutting force and is the main a significant reduction in power consumption and
determinant of the cutting power required if all ensured a smooth cut. HELIMILL heralded a new
other parameters are equal. The axial rake has design approach that is considered today as the
an effect on resolving the total cutting forces into acknowledged format in indexable milling, and put
components and acts on the tangential cutting the shaped rake face of an insert into the forefront.
force as well. With respect to milling cutters
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