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Milling Tools

Milling plays a key role in machining dies and molds. Indeed, milling tools remove the most
share of material, shaping a workpiece to a die or mold part. A conventional process planning
comprises rough, semi-finish and finish milling operations. The traditional approach to rough milling
is based on cutting with large depth and width of cut. Correspondingly, it demands high-power
machine tools with low spindle speeds for large milling tools. This way of machining provides
maximum productivity when cutting a soft material. Due to a die or mold has appropriate hardness
requirements and in addition, heavy-duty rough milling leads to significant residual stresses,
further heat treatment is necessary. The mentioned approach usually characterizes production of
large-sized die and mold parts that have considerable differences in depth or height. However,
some producers are still supporters of this method due to limitations of available machine tools,
CNC programs or traditional thinking in process planning. Over time, and as industrial innovations
developed, HFM became a relevant technique in roughing. It allows machining soft to pre-
hardened steels with small depth of cut and extremely high feed per tooth and leads to increased
productivity.
Milling Tools
HSM, another modern way of metal cutting, is intended first of all for finish milling of hard steels.
Nevertheless, it can be effective also for rough and semi-finish machining, particularly for small to
medium parts or in cases with slight differences in depth or height because it enables cutting hard
material directly. Further HSM development has resulted in trochoidal milling.

Yet one method of rough milling growing in popularity in the die and mold industry is plunge milling
(or plunging) with a tool feed direction towards the tool axis. It gives the opportunity for efficient
roughing of cavities and external surfaces with a complex shape (so called sculpturing operations).

The modern milling techniques, their advantages and problematic points and requirements of
cutting tools will be discussed on the following pages of the guide.

All typical milling operations are involved in die and mold manufacturing: 90˚ shoulder milling,
face milling, milling slots, contours and chamfers; and profile milling (the parallel definition of the
operations: shouldering, facing, slotting, countering, chamfering and profiling, also are often used
by professionals). The latter, including machining shaped 3D surfaces, is the pivot of die and mold
making. Milling tools are available in different configurations: indexable, that has replaceable cutting
inserts or whole cutting heads, and solid.

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