Sandvik Coromant Heat resistant super alloys - Manual (Page 68)

66
Cutter diameter
and position in face milling
The selection of milling cutter diameter is
usually made on the basis of the workpiece
width with the power availability of the
machine also being taken into account. The
position of the cutter in relation to the work-
piece engagement and the number of teeth
in contact are all vital factors for successful
operation.
When machining in a single pass, a cutter
diameter 20 to 30% larger than the work-
piece width is recommended. The milling
cutter should always be positioned off-
centre producing the thinnest chip on exit.
If several passes need to be taken, a radial
cut (a
e
) of 75% D
c
should be applied to
ensure good chip formation and suitable
cutting edge load.
Avoid positioning cutter on-centre.
Entry into and exit from the workpiece
considerations
Each time one of the milling cutter inserts
enters into cut, the cutting edge is sub-
jected to a varying shock load. The right
type of initial contact, and final contact,
between edge and material is an important
aspect of the milling process. Positioning
the cutter right as regards entry and exit of
the cutting edge is important – always avoid
a thick chip on exit.
Milling with indexable inserts