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Selection Guideline: How to Choose the Right Milling Tool
Putting the question of tool selection into broad perspective, the main side of the issue shall be
emphasized: cost per unit (CPU) for a part that is machined by the tool. In spite of the fact that
the tooling cost share in CPU is minor, the tool’s indirect influence on CPU reduction can be
considerable. Namely the tool, this small part of a manufacturing process, sometimes is a single
obstacle for a machine tool to run faster and thus to cut machining time.
Hence, for better productivity and as a result for lower CPU the most high-efficiency tool
should be used.
Another important aspect is versatility of the cutting tool, its ability to perform various milling
operations effectively. For example: shoulder milling, ramping and plunge milling. Such combinations
allow for using one tool for different applications and, when machining a part, shortening time
needed for tool change during machining.
An additional way of increasing versatility is using the tools with interchangeable precise cutting
heads, which render a possible head change when the tool or its holder is clamped into a machine
spindle and does not require time for setup procedures.

Taking these so obvious, but often left out points into consideration and speaking about the tool
selection more specifically, the analysis by chain: Application-Geometry-Grade (AGG) shall be
applied. In brief, AGG means the following commonly known checkpoints - questions, answer on
which allows for the tool choice:

Application What is the type of machining operation?
Workpiece: its material, hardness before the operation
Required accuracy and surface finish
Machining allowance
Machining strategy
Type of machining (light, medium, heavy) Milling Tools
What type of tool, in accordance to adaptation (a mill with shank, shell mill)?
Operation stability (good, bad)
Machine tool (sufficient/limited power, condition, spindle speed)
Coolant (coolant type: dry, wet; possibility of coolant throw spindle)
Geometry Which cutting geometry is recommended for machining the workpiece
for the above requirements? Both types of tools should be checked:
indexable and solid.
Grade Which grade of a cutting tool material is more suitable for machining the
workpiece for the above requirements?

Carbide Grades for Indexable Milling Inserts
The indexable inserts for milling the die and mold materials are produced from different tungsten
carbide grades, mostly coated by methods of physical or chemical vapor deposition (PVD and
CVD respectively).
PVD coatings have a wide distribution in milling inserts and solid carbide endmills because they
leave the cutting edges sharp. PVD coatings are applied at relatively low temperature
(about 500 ˚C).
CVD coatings are much thicker and that contributes to wear resistance. The CVD coatings are
applied at high temperature (approximately 1000 ˚C). Current technology enables improving CVD
process by moderate-temperature CVD (MT CVD) with its lower deposition temperatures. Further
steps in technology development include combinations of both coating methods: CVD and PVD.
ISCAR offers a rich program of the carbide grades for the milling inserts. We observe briefly the
more recent of them intended primarily for machining the popular die and mold materials. Except
for grade DT7150, the preferred grades, which are produced by SUMO TEC method, have

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Die and Mold