Tc 9-524 fundamentals of machine tools

8-6

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TC 9-524
Corner Rounding Milling Cutter
The corner-rounding milling cutter is a formed tooth cutter
used for milling rounded corners on workplaces up to and
including one-quarter of a circle. The size of the cutter is
specified by the radius of the circular form the cutter
produces, such as concave and convex cutters generally used
for such work as finishing spur gears, spiral gears, and worm
wheels. They may also be used to cut ratchets and spline
shafts.
Special Shaped-Formed Milling Cutter
Formed milling cutters have the advantage of being
adaptable to any specific shape for special operations. The
cutter is made specially for each specific job. In the field, a
fly cutter is formed by grinding a single point lathe cutter bit
for mounting in a bar, holder, or fly cutter arbor. The cutter
can be sharpened many times without destroying its shape.
Selection of Milling Cutters
Consider the following when choosing milling cutters:
45° angular cuts may either be made with a 45° single-
angle milling cutter while the workpiece is held in a
swivel vise, or with an end milling cutter while the
workpiece is set at the required angle in a universal vise.
The harder the material, the greater will be the heat that
is generated in cutting. Cutters should be selected for
their heat-resisting properties,
Use a coarse-tooth milling cutter for roughing cuts and a
finer-toothed milling cutter for light cuts and finishing
operations.
When milling stock to length, the choice of using a pair
of side milling cutters to straddle the workpiece, a single-
side milling cutter, or an end milling cutter will depend
upon the number of pieces to be cut.
Some operations can be done with more than one type of
cutter such as in milling the square end on a shaft or
High-speed steel, stellite, and cemented carbide cutters
reamer shank. In this case, one or two side milling
have a distinct advantage of being capable of rapid
cutters, a fly cutter, or an end milling cutter may be used.
However, for the majority of operations, cutters are
production when used on a machine that can reach the
proper speed.
specially designed and named for the operation they are
to accomplish.